Does anyone know what problems one might encounter using the Reflex?
Where is the fiber optic light collector placed?

Does the Tritium work properly in the dark?

ETA: Doing some reading in the forum... IBTUTSP (In Before the "Use the search" people)

The reason I ask is the PS90/P90 comes with a Ring Sight MC-10-80 which seems to operate on the same principle. I can see a large number of Reflex haters and probably why: the triangle on the Trijicon probably washes out when aiming at bright surfaces (sky, white buildings, snow, etc...)

It seems white is an even worse color choice than bright yellow. The MC-10-80 also has darkened filters.

pros seem to be it doesn't use batteries and is fairly bulletproof.
Con is that it has no tactical capabilities.

I owned one a while ago and wish I never sold it. You will need a polarizing filter as the faint yellow gets blurred out in very bright light but still visible. Fiberoptic light gathering ability is on the face. Once dialed in these hold true and they are set intensity always on but not scope like looking through with paralax as you get with tube style aimpoint yet heads up like an Eotech but less the annoying red lazer glair.  Once again best feature, always on no adjustment, heads up no paralax from tube, polarizing filter added as image super imposes over non-dominant eye. They used to make a 6MOA triangle model (rare)- very nice just put the point where you want it to hit, now they have a 12MOA I believe, the 4MOA dot standard USSF.

i have the meprolight reflex and its better than the trijicon,though it has 4.5moa dot.
sold my aimpoint for it and was happy i did, love having use of no batteries, and at night the power source somewhat acts like it has some illumination but not like having night vision.  
i guareentee you that 90% of the people bashing the reflex systems have never had one. meprolight usally run $550 plus you should buy the polization filter for it. so its an investment but worth it. ebay probaly be you best bet

I have a Trijicon Reflex II on my shotgun that I use for 3-gun matches and I love it.  Mine has a 2 moa amber dot.  With the polarizing filter I don't get "any" washout aiming at bright objects.  I replaced the high thumb screw mount that came on it with an ARMS 15 mount that puts it right on the rail.  Very low profile.  I didn't like it on my AR's but it is perfect for my shoty.  I run an Aimpoint and a Compace ACOG on my AR's.

MadDog

I have a Reflex NSN on my AR6721 right now and I love it.  I have had it for several years an dhave had no problems with it.  It does get a little bit of wash when I use my M962 weaponlight, but with the filter, it is just fine.  I really prefer it anymore to my POS EOTech.

Quoted: Does anyone know what problems one might encounter using the Reflex?

Washout is it's biggest issue.  I loved mine till I tried aiming into a lit area while standing in a low lit area.  Under a tree line or inside a house aiming into a well lit area, or an area thats under direct sunlight causes the dot to get very faint.

Does the Tritium work properly in the dark?

Yes, but the tinted glass turns your reflex into an Armson OEG.  The Aimpoint excels at night cause the glass is clear and you can adjust the dots brightness.

The only reason I could fault the Aimpoint is for batteries but they last forever in one.

Quoted: Does anyone know what problems one might encounter using the Reflex?

1) Washout - particularly when you are in a dim area shooting into a bright area
2) Too Bright - I've seen dots that were so bright they looked like they were 12moa - this happens when shooting toward the west when the sun was low in the sky (Original model Reflex)
3) Mud and snow can block the emitter preventing the display from functioning.
4) Dusk/Dawn there is a time when there isn't enough ambient light to power the reticule, and the tritium lamp isn't bright enough either.  (no big deal on a range-only optic).

Where is the fiber optic light collector placed?

The front of the sight (toward the target area).

Does the Tritium work properly in the dark?

Very well.

pros seem to be it doesn't use batteries and is fairly bulletproof.

The original NSN Reflexes did have a few issues in the field.  They are not as sturdy as Aimpoints or EOTechs, but they are tougher than most commercial red-dots.

Con is that it has no tactical capabilities.

I can't comment on the P-90's sight, but the Trijicon Reflex worked farily well.  It has been eclipsed by better sights (Aimpoint & EOTech) but it was 'tactical' when there were few other choices.

How are the current RX01NSN models? They include the polarizing filter and the AR-15 flat top mount. Will it clear the front A2 FSB?

It's about $200 less than the Tripower setup with the ARMS mount and 1/2" spacer. I understand the Tripower allows cyalum light sticks and battery power.

The EOTech and Aimpoints are turnoffs to me because they rely solely on battery power.

My last resort would be some type of CQ scope.

Quoted: How are the current RX01NSN models? They include the polarizing filter and the AR-15 flat top mount. Will it clear the front A2 FSB?

I actually prefer the older models w/o the filter.  Nothing to dick with and they were brighter at night.

The standard flattop mounts puts the irons in the lower 1/3 of the display.

The EOTech and Aimpoints are turnoffs to me because they rely solely on battery power.

You must ride a horse then, as automobiles rely on battery power...

The Aimpoints life is so long, all you gotta remember to do is change the battery on your birthday..

The EOTech is no slouch, but has the advantage of being able to use rechargeable batteries.  Theoretically you could run an EOTech 4 times longer on a 2 pairs of NiMH and a solar recharger than the tritium lamps will last.

There are advantages to each system.

Cars rely on batteries solely for starting/ignition and then the alternators take over using the batteries as filtering capacitors and for energy storage. If you rely solely on battery power to run a car, these puny car batteries have a reserve capacity of less than 1 hour or so assuming conservative draw.

You do have a point though. I would like the ability to switch from the DCH to the EOTech without bringing a 7/64" allen wrench with me. I thought i saw a LaRue EOTEch mount somewhere...

Quoted: Cars rely on batteries solely for starting/ignition and then the alternators take over using the batteries as filtering capacitors and for energy storage. If you rely solely on battery power to run a car, these puny car batteries have a reserve capacity of less than 1 hour or so assuming conservative draw. You do have a point though. I would like the ability to switch from the DCH to the EOTech without bringing a 7/64" allen wrench with me. I thought i saw a LaRue EOTEch mount somewhere...

Alot of newer autos need a fully charged and good cell battery to run. Our 1998 Blazers battery started leaking, caused a dead cell and it would only run as long as the jump lasted, same with our 2003 Explorer (dealer didnt get the neg cable tight and I had an awful time until I checked over what they had done.)

But back to the Eotechs and battery life. I have found that I usually get 4-6 mos out of the batteries and I just keep some spares in my range bag.

Its funny how so many AR guys carry backup parts...springs, bolt etc... but do not want to carry a couple of batteries?

Anyways, I have the Eotechs, Reflex and had an Aimpoint, and I prefer the Eotechs. The sight pic is large and quick to use, reticle is adj for brightness so just dim it for the "redness". And my newer 550 series Eotech has the thumbscrew on the internal mount. It also co-witnesses with the Arms #40 perfectly.

Find what you like best and enjoy,

Quoted: Cars rely on batteries solely for starting/ignition

Dead battery is a non-starting car.  period will not run at all.  Dead battery in an optic means you use the BUIS.  BIG difference.  BTW I have owned cars where if the alternator died the car died as well (even though the battery had power) and it happend in the days before cell phones...

You do have a point though. I would like the ability to switch from the DCH to the EOTech without bringing a 7/64" allen wrench with me.

Besides the LaRue mount you can use the included thumbscrew mount (which worked well for me prior to the LaRue mount) or the YHM BIG thumbscrew mount (which is even easier to use than the stock one).