Where do you live?

I'm gonna guess that JRA in Medford has about the best demo fleet selection around if you live close to try some out.

Pedal Power in Acton has a 2012 Specialized 29'r Stumpjumper FSR Comp test bike (I think quite a few Spec. shops do so check) which I had for 3 days. 130mm travel F/B and I could immediately do things on that bike I can't on my converted 650B Prophet. Shocking really, so at least test out a 29'r to see how you like it. Personally I wouldn't purchase a 26" bike again for "all around use". 650B or 29'r. Like it or not the 650B size is now moving full steam ahead with 10+ manufacturers (I'm losing count) producing bikes along with plenty of new tire and rim choices.

3K will get you a very nice bike. 2103 bikes are rolling in now so look for 2012 or even 2011 leftovers. I found and purchased 2 leftover 2010 bikes for my son and daughter (Gary Fisher Roscoe 1 and Specialized Safire Comp) for 1/2 their original MSRP. Deals are out there.