For a glock carry pistol

What is the game changer one over the other?

I recently got the RMR HD, and I really like the auto brightness. It works extremely well imo.

I have used an RCR but it was awhile ago, and I haven't had the chance to compare them side by side.

Is either even readily available? Tagging for replies.

No I have yet to see where it can be bought.

We got both in Nov. after back ordering them the day they were announced last August.  RMR HDs come in now and then, haven't heard much about RCR

Picked one up from Battle Werx a few weeks ago.

I have both. I appreciate the RCR however the front facing light sensor on the RMR HD skews me towards it. It’s that good. The larger window is a bonus. The RCR is essentially just an enclosed RMR. There’s nothing really awe inducing about it.

Get the RMR HD.

I really think they should of put the light sensor on the RCR also. I don't know why they couldn't, maybe the battery on top doesn't give it room for the wiring/sensor. I think it would of been an absolute winner.

For anyone looking for an RMR HD sign up for notifications at Range USA. I was able to get one a couple weeks ago, and got another one yesterday.

If you really want and enclosed RDS, go Acro. Controls are on one side and easy to activate. The mount is superior to the capstan screw arrangement Trijicon decided to use. No auto adjust on the brightness, but it's not really needed if you set the dot up right. Trijicon missed the mark with the RCR by not adopting a clamp style mount like the Acro or 509T. With Glock and S&W offering factory Acro footprint pistols to law enforcement it's quickly becoming a very popular option as it's easy to replace the battery and easy to R&R the optic with no thread locker to mess with.

For a gun that's milled for an RMR already, no reason not to go RMR HD. The downsides of an open emitter are overblown. I say this as someone who has pretty much switched to the Acro save for 1 pistol and piggyback applications (standard RMR is still king here due to size).

You live in Texas, I can't imagine the weather is such that you would significantly benefit from a closed emitter. Unless you're open carrying and a lot of dust and sand is kicking up around you all day.

The problem with the RMR HD is if you want to use it for any Level 2 or 3 holster like the Safariland 6xxx types, because it will not fit them without modification.   Whereas, the RCR will fit nicely into said holster types.

The RMR HD's foward cant (necessary to accommodate the battery cover placement) can cause it to take a lot of brass strikes as well, so just FYI it will need to be cleaned.  

The RMR HD's autobrightness feature everyone above has pointed out, is amazing and something that should be on all red dots.  

The larger RMR HD's window is nice for tracking the dot under recoil.  A good analogy I heard describing the larger window's benefit is that it's like playing catch and being able to watch the baseball come towards you. Whereas, having the smaller RMR or RCR window is like having someone toss a ball at you from the side and you only see it at the last second before you catch it.  However, the HD's window size is only 17.2mm tall compared to the RCR's at 16.2mm.  So, it's not a significant increase in window size, especially when compared to the SRO's 22.5mm window.  

MILSPEC Mojo did a good presentation of the advantage of the enclosed emitter (specifically his ACRO) over the single open emitter style in one of his videos awhile back.  Essentially, he said that he found it easier to center enclosed emitters that have two panes of glass than open emitters with one pane of glass. He used the analogy of looking at any i-phone screen compared to looking through a tube, it's easier to see right away see when the tube is slightly out of your center of sight compared to the i-phone screen.   Now MILSPEC Mojo admitted that training sort of negates this advantage, because if your presenting the gun correctly you're going to be naturally centered on the sight.  Still, it's something I thought was an interesting point.

If it were a concealed carry pistol I'd prefer the RMR HD, but I'm fine with taking the larger footprint.  If it were more for a "do it" all general purpose pistol and especially if it were for anything being carried openly I'd want the RCR.  Keep in mind to that the RCR will not work with ZEV type slides that use their mounting hole style, because the screws are not made for them. I think ZEV and Brownells slides may fall into that category of slides that will not work with the RCR.  

I lucked up on a RMR HD from Staccato. I mounted it on my C2. I love the optic, but it sits further forward than the RMR, so I'm running into holster fitment issues. Nothing a Dremel won't fix, but I'm hoping for a different mounting plate sooner or later from Dawson or someone to scoot it back. I could give less than a shit about the rear sight

RMR mounted to my Glock 45 using Forward Controls Design plate.

How are you liking the C2?  Is it your go-to concealed carry? I have been looking at the CS.

Absolutely love the RMR HD.  The light sensor works amazing well.  Fits fine in my Safariland without modification and have not had any brass strikes.  Don't really see a reason to go with the RCR unless you absolutely need an enclosed emitter.