I think if you like the bike *and it fits*, go for it. I ride a 13 year old ti hardtail that fits me very well. I think it is still competative for XC, IMHO. The only thing lacking is the outdated fork, which for this particular frame is maxed out at 65mm. I lose some on the downhills compared to the newer rigs, but I think I can make it up on the climbs. I would think a 98 would be built for 80mm forks-so you still have up to date fork options. Discs? Some are nice, but I am more than happy with my V's. Really, a front disc would be all you need, should you want to upgrade in the future.
Depends what floats your boat. There are some sweet aluminum bikes out there too. Not to mention that you would be starting with everything new.