Greetings,

I'd like to get a couple of MRDS sights to accompany rifles with either a 5x prism sight, or a full on scope.  Looking to put them on offset mounts.  I'm fairly versed in fuller sized RDS's, but the mini's...not so much.

From what I see, there are basically open and closed emitter designs.  Any reason why an open emitter is better?  I'd think closed allows for an unimpeded projection of the dot on the lens?

In looking at some Holosun options, they are using a battery size I've never seen before (CR1632 3V Lithium Coin).  Do the majority of MRDS's not use the more standard CR2032?

Of the Trijicon RMR's, which would you recommend?

Any preferred mounts for an off set?

I've been very happy with Leupold's Deltapoint Pro mini-RDS.  I bought the first when they first came out.  Used and abused it.  Performed flawlessly.  Its the primary in my HD carbine.  The second is offset mounted 45 degrees with a mid powered scope up top on a precision Recce.  I've had no issues with them being open emitter designs.  They have much larger screen and FOV than RMR and most closed tube red dots.  Battery life is in years since they are motion activated and have been 100% reliable.  Can be daylight bright. Current models are now night vision compatable.

The Deltapoint Pro is kind of fragile. I have three and broke one from a drop. See the Aaron Cowan/Sage Dynamics review.

I am just not a huge 45 degree offset fan. It is awkward to me due to having to flare my elbows to employ comfortably. Especially on larger scope guns. You can't use it shooting weak hand. I have 5 pistol dots currently. All are open emitter. An SRO, RMR, and 3 DPP.

Closed emitter pistol sight designs currently produced are all kind of crappy in some way IMO. None are optically as good as the Deltapoint Pro. Really, almost nothing is... at least purely optically. The Deltapoint Pro has the easiest to change battery, best motion activation, clear low tint glass, big window, aspherically corrected to have no magnification or distortion, and a clean dot. The only negatives are thickness on a pistol, the one button brightness control, and the slight fragility. It is relatively cheap too at LE prices.

The whole thing about open emitter designs being susceptible to rain is overblown IMO. You give it a single shake and the dot is back. It is susceptible to a tiny mud glob landing directly in the window of the emitter to block the dot vs the whole rear of the closed emitter window needing to be covered to make it impossible to see the dot. You need to determine if that is an acceptable risk or not for yourself. I will say this... most closed emitter pistol dots have such a small rear window anyway  the difference in mud blob size to disable is negligible. A quick wipe with a clean cloth (inside of shirt sleeve, etc.) gets either back up and working faster than deploying your flip up BUIS. I will say leaning out the passenger side of a side by side shooting at hogs while driving through sloppy mud puddles is NOT the Forte of open emitter mini dots.

Closed emitter pistol dots give up the main advantage of using a pistol dot in the first place... weight and bulk. I would just use a T1, T2, or Romeo 5 if I wanted a closed emitter, 45 degree or not. You will have a tougher optic, more battery life, and the weight/bulk penalty is not as hard to swallow when comparing a T1 sized optic to a closed emitter pistol dot. Just one person's perspective.

I respectfully disagree about the DeltaPoint being fragile.  I have several.  One is the primary on a carbine that I clumsily dropped on a concrete surface.  It landed optic first.  Only cosmetic scratching of the spring steel hood surrounding the lens. No functional damage at all.  I just touched up the scratches with cold blue.  Its still serving well now over six years.  Another is offset to a midpowered scope on a hunting rifle that been lugged through rough terrain in terrible weather with no ill effect,

You can break any optic.  Its no less fragile than the low powered scopes used on duty rifles.  The current US military issue sidearm has its slide cut for use of the DeltaPoint.

I do agree with the remainder of the excellent post.  Offset works better for me, though, compared to top mounting above the scope.  That's a matter of personal preference.

RM06 or RM09