REAP-IR 35mm series 1 v.s. series 2
REAPv1 has inline battery compartment vs REAPv2 has vertical battery compartment. A few "heavy" users of the REAPv1 had recoil shutoff issues and apparently trijicon decided to fix the problem and the REAPv2 was the fix. I've had patrols and snipes and mk2s and mk3s and never had a recoil shut off even on one of those thermals (I have had a number of recoil shut off events on other thermals). But +2 for the reap v2 on this point, that was the whole reason they did the v2.
The plus of the verticle battery compartment is somewhat offset by its being more difficult to use with after market battery packs/extenders, so this is a +1 for the v1.
The v1 has a skeet mount on one side and a pic rail on the other. The v2 has a pic rail on both sides ...
The plus of the skeet mount is that this allows the v1 to be helmet mounted ... and at least for me ... it works fine ... I expected it not to work fine .. .but it does ... even at 2.5x .. with the 14 being 1x ... so this is a +1 for the v1 in my book.
Both the v1 and v2 can use the other pic rail to mount range finders like RAPTAR or Radius ... or a laser pointer like a steiner otal ... or a day sight like an RMR. So they are even on this score.
The v2 can use the other other pic rail to wpns mount ... the v1 can use the skeet mount with a skeet wpns mount to wpns mount. That's how I do it .. I use the skeet wpns mount for the v1 and the patrol ... so I call that even on this score.
The v2 19mm can be upgraded to the 35mm or the 60mm. And the v2 35mm can be upgaded to the 60mm ... the v1 cannot be upgraded. This is +1 for the v2.
The v1 reap I had had clipon mode ... but I'm not sure any of the currently available v1 or v2 have this ... so if you wanted clipon mode, you might have to get a used v1 and ask if it has clipon mode. I'd give a +0.5 to the older v1s on this score.
Well that's all I can think of in terms of differences. So if I'm counting correctly, the v2 wins by + 0.5 ... but that really depends on whether you want to head mount your thermal or whether you want to use an extended battery pack ... if you want either or both of those ... the v1 comes out ahead.
You might also be able to pick up a v1 at a lower price, since some people think they are worth less !!
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For me, I "hate" zeroing any of the joystick housing units ... the patrol, the reap, the snipe ... its probably just me ... but I'll need one click ... and I'm touch the joy stick ... and nothing ... and touch the joy stick and nothing ... and touch the joy stick ... and click 3 clicks instead of the one I wanted ... and it doesn't happen once in a blue moon, it happens 1 or 2 times out of 3 ... its a pain in the butt for me ...
The turrets on the mk2/mk3 are positive clicks ... and they work great in -10F temps with gloved hands .. if I want a trijicon dedicated thermal scope, give me a mk2/mk3 ...
Though actually I'm a clipon bigot ... so give me a utc-xii