I received my XIM3 today and have been playing Blops for a bit now. Just started playing MP... it's funny to see a level 1 (now 6) playing with all these high level multiple prestiged players. Took a little while to get to use to the game... mostly I don't know the maps, etc. Most of my deaths was because I did something stupid or someone snuck up behind me. Many of the 1 on 1's I won... shoot I even came out on top with 1 on 2 and 3's several times. Not to say that I couldn't do it with a controller but it seems like I've done it more often. The control is awesome though and I finished the first match ever with a positive score! Haha. My KD on MW and MW2 was in the positives but around 1.2/3 so we'll see how it is in Blops. I'm by no means great at the game, but I can tell that I'd be doing MUCH worse without the XIM.
Before plugging it in to my 360, I ran it in PC mode and updated the firmware to the beta. Easy as pie and worked like a charm. I'm running Win7 x64 just in case people had any concerns on OS compatibility, which we shouldn't because I'm sure OBsIV checked all that.
Setting up was quite easy especially after watching the youtube videos. At first I was a bit confused on the config settings but I watched the videos and everything was fine. The Quick-guide is nice addition as well. The XIM OS interface is quick (not laggy or slow) and easy to understand and navigate (I was afraid it'd be sluggish or something). I kind of wish there was a full on manual but I suppose that's what the forums are for right?
I'm using a Logitech G5 (2000 dpi max) and it works fine although I'm looking to get a G500 or G9X. I have the Belkin n52te and the XIM didn't like it when I tried assigning buttons. I would usually take the time and try to figure out what the problem was but I was too excited to play. I ditched the n52te and plugged in my old Saitek gaming keyboard that bigbobross showed in his video and it works fine, so I don't know why yours wouldn't work bigbob.
The XIM is pretty much perfect as far as I'm concerned. The KBM combo is absolutely beast and I share the same positive sentiments as the others on here. I really don't know what else to say but no matter how cliche, this thing is AWESOME. It's a former PC gamer's dream come true.
One thing that frightened me was when I, by accident, unplugged my mouse the screen went completely green on me. I was like oh $(*&@^$!... don't tell me this is like the BSOD. I just turned off my 360 and turned it back on and the XIM booted back up just fine.
The scent coming off this thing is somewhat overwhelming at first, but I do like the new tennis ball can smell.

We'll see how this goes! Thanks OBsIV and team for such a wonderful product and I wish you the best in your current and future endeavors!
Also, I do have the GT Max adapter for the PS3 and will attempt to try it tonight... if not tonight than tomorrow and I will post that information up whenever I can.
EDIT: Add me on XBL if you want. Please state that you're from Xim3 forums.
EG0N PAX (<--that's a zero in there)
Also check out the XBL list in the General Discussion section.