I replaced a 2000 TJ Sahara with a 2005 LJ Rubicon and the difference was substantial. The extra length may not sound like much, but it is a big difference in usable cargo area and ride quality. I really love that LJ and thought I'd never sell her. Then I drove a 2012 Unlimited Rubicon and I knew I had to have it. So, now there is a bright white JKUR in the driveway and my beloved LJ is for sale. It was a great second car, but the JK can be my only car. Of the five Jeeps I've owned (CJ, YJ, TJ, LJ, and JK) the LJ is my favorite, but the JK is rapidly becoming a real contender.
BTW, I never even considered a JK until the Pentastar. The 2011 interior was a big plus, too, but the engine is what sold me. If you're looking at 2011 and earlier, for my money, the LJ is the superior vehicle.
Kerry