I have seen a lot of questions about these and wanted to give some advice. Between me and my friends we have had 9 of them to test.

First off , yes they do hold zero even on a shotgun or .308 . All of them had no problem with recoil so the guys who may have had a problem got an odd ball.

Second, but most important is there are 2 versions of them.  I do not mean the short and high rise but 2 actual different versions. The first has the diode at the bottom of the lense and the dial has lines above each number.  The second has the diode at an angle to the lense and the dial has lines between each number and the dial is slightly taller. From a closed package on the shelf the only way to tell the difference would be the dial sense the diode is hidden by the rubber cover,

The version with the diode at the bottom has some issues.  The dot is not nearly as bright and the dot will not be seen on the top 1/3 of the lense?  Avoid this version, even though I prefer the diode on the bottom and like the dial better.  Even on this version the dot is usably bright but the dot not being seen on the top of the scope is a big problem for me.
The version with the diode at an angle is very nice and bright and the dot does not go away as you look at the top portion of the scope.

I do not actually know if one version came before another or if they are from different factories or maybe both are meant to be equal but the bottom diode version has had quality control issues?  I can say that the angled diode version with the lines on the dial between the numbers is a great red dot and comparable to a T-1. I would have no problem taking it into a war zone the same as a high end scope. They also seem to get closer to 5000 hours battery life when left on 3-4 setting which is a lot and more than advertised. If you do have the bottom diode version and can live with the dot not being seen on the top 1/3 of the picture then you still have a good red dot just realize your dot is much less bright than the other version and in a bright snow type situation it may be to dim.

Over all using the angled diode version as my sample I would say the TRS 25 is as good as you can get until you spend $600 on an Aimpoint T-1. If you can afford a T-1 then get it but if you have many rifles like me and a small stack of money then the TRS is very close on every aspect to the T-1, even clarity. I do have a T-1 but other than night vision use I would never buy another when the TRS is soooo much cheaper.

I hope this helps some people out and explains why some people have gave reviews that the dot was to dim.  They most likely have the bottom diode version.

Another way to tell is the shitty version doesn't come with the battery installed and it can be seen in its package through the back of the blister pack where the manual is at. I've dealt with this issue too and was very agitated to say the least.

I have one that has settings ranging from dim to nuclear. I love it, just wish there was a good mount for it. I'm using a pair of risers stacked on each other to get a lower 1/4 cowitness.

Here toy go for mount. Works great
http://www.ebay.com/itm/1-High-3-Slot-Hi-Profile-Compact-Riser-Mount-UTG-MNT-RS10S3-/291027410680?pt=LH_DefaultDomain_0&hash=item43c295def8

My angled diode TRS-25 would not hold zero on a tactical shotgun.  It sighted in fine with a couple slugs.  Switched to heavy 00B loads on shot number 6 it went out.  No dot.  Dead.  It later came back to life after putting the shotgun away for an hour or so, and shooting something else.  Fired another round and it was 6 inches high and right.  It's on a .22LR now.  Ok for that use.  Sorry to have to disagree.

The results of a single sight really don't amount to a conclusion on reliablity, the only Eotech I have owned died, the 8 cheaper micro dots (sparc, trs-25, primary arms) have all functioned and held zero.

The newer Primary Arms (the ones that came out in the last year or so), now get battery life similar to the TRS-25s, neither are aimpoint like but a big improvement and like 6 months or so of continuous use.

When the failure of the single sight is YOUR sight, it matters a lot.

Maybe not a statistically valid sample, but its my sight and it will not handle recoil.  I did a bit of on-line research after my failure to see if perhaps it was a fluke.  There is a very interesting drop test of the TRS-25 that seems applicable to my situation.  In the drop tests, it did not hold up very well (drops on soft loose sand from only waist high), and the manner of failure was similar (although not identical) to  my  shotgun recoil point shift and eventual failure.  I think the TRS-25 is a great sight for a .22LR and maybe even an AR15 that is not going to get knocked around.  But it is vulnerable to impact and heavy recoil.  My conclusion is that it is not very rugged.

TRS-25 Full Test with Drop Test Failures

As far as concluding that the TRS-25 is "as good as it gets until you get to $600 T-1" or words to that effect, I must respectfully disagree and suggest that a $189 shipped Lucid M7 micro dot is much better.  

Yes, it costs about twice as much, but well under $200 and only 1/3 of $600.  It is rugged.  It handles shotgun loads faithfully.  It has a much better CQB reticle (donut dot), has auto illumination intensity with manual over-ride and auto shut off after two hours.  It has very clear glass and you can't see the diode at all unless you really get seriously off axis.  It does not have the internal reflection issues either. It runs on a single AAA battery (much greater availability anywhere 24/7) and even has tethered turrets and battery cap.  

I think that microdot optic design is evolving.   Lucid's M7 is not the only one in that mid-price range above the TRS-25 and below T-1 or H-1 optics.   Those optics in that mid range are getting better all the time.  Time marches on.  My TRS-25 is now on a .22LR and I have two Lucid M7's.  One of them is on the tactical shotgun.  Once I saw that it solved my recoil problem I got a second one.  The other is on an ADM QD mount on an AR build that also shares a LaRue QD mounted tactical scope for longer range work.  I can swap them back and forth with excellent return to zero.  I run the M7 90% of the time.

Mine's on an AR pistol/future SBR with a brake on it and seems to be fine.