Ok, I have too many standard rail accessories to go replacing them all with HK monopo-, er, products. So....which rail adapters work well, and are there any that suck? This is for my full size USP .45 Tactical.

I have seen some from GG&G, Lasermax, KZ (?) and Promag. I have never heard or experienced anything good from promag...but it and the KZ seem very affordable, and it's not like they have moving parts or something.

Opinions? (Preferably from first hand experience?)

if the KZ is like the original GG&G don't get it.  I didn't like it.  I can't remember exactly what it was, but the newer design was supossedly better.

You could always do what I did...  I get brave when I'm drunk

Man that was brave! It came out excellent though. Must .....resist .......temptation...

Whatd you use?  I havent seen that before, has anyone else done it?  Is there anything else that you need to do, or is it just the slot that keeps the normal lights from fitting?

Dremeled the rail slots out to the front end, and notched it for the cross bar?

I don't have the interior fortitude.

I've never seen the KZ, I think it's a lot like the slimline GG&G. I called Bladetech, they said their holster only works with the GG&G or surefire, and that's where I'll be getting my holster, so...

Looks like GG&G.

i've heard that gg&g ones kept coming loose and not holding zero. I have 2 surefires, one for my full size, one for my compact and these things are dead nuts when it comes to keeping zero, one thing, good luck finding a holster, most will not work.

Shawn

I have two GG&G and I have not had a second's trouble out of either.  Make sure you have the right rail on your pistol.  All of mine are .45 so since their frames are larger maybe that is the reason I have had no trouble but whether on Compact or full size, they have been working for me.  I also have the Surefire, too expensive and not one bit better than the GG&G, as well as the Pro-Mag.  It works but hangs the light down too far.  I did a picture post on here and on HKPRO comparing the three.  
In summary of the post, if money is a major concern, Pro-Mag will work just fine.  If money is not a concern, IMO GG&G is the best for the buck, if you must have the Surefire name and have the bucks, then their adapter will work just fine.  It looks almost identical to the GG&G.
The new adapter from LaserMax is the about mid cost between the ProMag and GG&G, looks like the GG&G, but I do not have one and I doubt I will be buying one.  I am just not in the market for any more rail adapters.

I have used them on Compact 45s and Tactical 45s with the TLR-2 and they have not marked the frame or shifted any at all, none of them.

Well also I saw a surefire on this forum go for $12.00 shipped once also, missed out on that one by like 5 minutes. Another thing maybe the person that used the GC&G one didn't do was to use a little loktite, which I did with the surefires also.