What is the best material- CF or Ti? Think you have to include Steel and Aluminium in that aswell. Not talking about the run of the mill frames though- Talking the better quality ones. Ti Can be very flexible- CF can be very stiff OR flexible- Aluminium can give a very harsh ride and steel--(Aswell as the other materials) can be heavy.

But the reverse can be true on all the materials again. Best ride I ever had was on a Ti frame- till I got the Boreas. and then when the TCR-C frame got built up- I was disapointed till I got it sorted. And my favourite Offroad ride for comfort was a Fuji-Steel frame that was built up and weighed 19lbs.(That is light for an MTB)

Only point to make is that you need quality. Whether that is by going top end complete bike- or buying just the frame and building up with your own Custom build- The heart of any bike is the frame and that is where the cost should go on any build.

So its time to get out- Find the shops selling the quality bikes and get test riding. One of those will stand out as your next bike.