I sold my DH bike and I am buying a 6 inch bike that I will ride all my 4+hour ride on and we have pretty good rides around here.. travel and weight isnt that important.. rotational weight with your wheel set and tires is the biggest thing, and so many bikes now are amazing how well they pedel for how much travel they have..
I know that people will boo me out for this but I was sponsored by mongoose and rode there Boot'r Team last year and I will be riding a Khyber this year.. I strongly sugest you check out the mongoose line, they are great bike. The freedrive suspension system works amazingly well and I have loved it, and these bikes are the best bang for the buck of any new bike out there..
the Khyber that I am riding, I can shuttle it and have ridden some of the burliest DH courses around here on it, and then I swap a wheel set out and I can easily ride 5+ hour epic XC rides on it.. Its one of those bikes that istn the best at anything, but it does just about every thing short of dirtjumps and trial very very well..
I do remomend you check out the Mongoose line.. the teocali would be a bitchin trail bike too.. my dad has one on order.