First one is cool. The colors there look awesome and lively. Looks like it could do nicely in like some nature magazine or something, seems professional
A quick glance at the second one makes it look a bit blurry, but if you look more closely, its got a nice focus. The sharpness on the snout does make it look a bit awkward, but I also like how it is now. Has an effect like since his eyes are closed and stuff, that it's more distant...
For the third, what sqrage said. Maybe if we saw the whole thing from a distance, it'd look fine, but at this closer view where it doesn't even fit in the browser, heh, the background does distract from the tiger.
I do know this - xenforo dropped the ball by not keeping the vbulletin reputation comments as a feature. The loss of the Reputation comments data when we switched to Xenforo really was the death knell for the site when it came to all the users that left. I know I missed it so much and I got way less interested in the site when that feature was gone and I run the site.