I upgraded last October from my TJ Sport to an 05 Rubicon and love it. It was geared a bit low at first, but a 4inch lift and 33s fixed it. Personally, I dislike the look and snow performance of 33 12.5s, so I went with 285 75 r16s which are basically similary to a 33 10.5 but are much easier to find. I think the stance and performance are awesome. My lift had a T case lowering kit and I am unhappy with the shifter and how close it comes to the console on the inside and after trimming it and botching it, I am saving for a CV drive shaft and will then take the T case lowering kit out and put the T case back where it belongs, an inch higher. Then I'll buy a new front console to fix the trimming mess I created.
Regarding TJ vs JK, I'm a fan of the TJ and had to seriously consider a 1 yr old TJ or a new JK with lifetime warranty. I plan on keeping this one forever, so the lifetime warranty is very appealing. However, the 300 6 is bulletproof and there are parts everywhere from Alaska to South America if needed, and this engine has proven itself time and time again. I like the TJ because it's narrower and fill fit on smaller trails, it also looks more like a CJ to me. Good luck on your quest, and let us know what you decide! Cheers!