Each big company is going to have a great value in one or two segments, Specialized, Trek, Giant, Santa Cruz. All have competitive pricing when really comparing apples to apples, which is hard to do unless you are a bike geek.
ANYTHING will be far better than your 10 year old trek, not bashing on it but bikes are like everything else, the ENTIRE industry is different about every five years.
By the sounds of your riding, you do want a 29er XC, possibly Hardtail. The big wheels will help eat up small bumps and roll way better for your situation than 26".
My honest opinion on brand, don't worry about it, ALL bigger companies make a very capable bike for your demands, pick a SHOP you want to work with, if you don't already have a shop. If you are THEIR customer and they are YOUR shop, ask them honestly who they get the best service from, on a rep and manufacturer level. THAT is the bike you want to buy, here is why. They have the best relationship with that brand, they sell the most of that brand so they know it inside and out well and if they have that relationship with the manufacturer/ rep it will be the easiest to warrantee or service should something go wrong.
Like you mentioned, you have had that trek 10 years, you will probably have this one another 10, you want to work with guys who know it well. buy a shop not a bike