HT vs DS?
I've struggled with this question... and have at least temporarily resolved it in my mind. My primary beef with FS has been the bob/inefficiency that tends to tire me out on climbs (I'm pushin 50). Plus the maintenance headache and COST!!! I've owned 4-bar suspension and single pivot bikes and BOTH were a royal pain (in my opinion) to maintain. Blow a shock and you're out at least $250 if not more. Annual rebuilds are a must. I always felt one stroke of bad luck away from a blown (or problematic) shock. To me that creates a seriously flawed situation. And the more sophisticated your suspension setup, the more problematic it can ultimately be.
My solution: "passive" suspension... I ride steel 29er hardtails. I love the feel of steel; it flexes, it's reasonably priced, and it LASTS!!!! (I had a Ti bike last year that I busted... I'm stickin with steel). My XC ride is a Niner MCR with a Reba 80mm fork. The 853 steel frame is really nice, and provides a small amount of flex. Add a Brooks leather saddle and tubeless tires (at reasonably low pressure), it's SUPER comfy! It also feels light (strangely enough), AND I feel I can climb all day in the saddle without getting totally worn out. Moreover I'm starting to ride technical sections as well (if not better) than I did on my 26er FS, with fewer endos.
I also ride a fully-rigid Karate Monkey 29er as a single speed. This bike is SO MUCH fun to ride, once you get used to it the ride is actually quite comfortable. Between the frame flex, Brooks B17 saddle (a MUST), carbon seatpost, and Panaracer Rampage tires there is plenty of cush to take the edge off... The simplicity and responsiveness of this bike make it so enjoyable and comfortable to ride.
In fact, I just picked up a Salsa Cromoto rigid fork for my Niner... I need to have that simple solution as a fallback (when my Reba fails or is out getting Pushed). I plan to periodically switch out the Reba fork for the rigid fork... Riding rigid (even at my age) has so many other benefits in terms of making me a better rider (ie having to pick well-thought-out lines), having lighter, stiffer, more responsive steering... It definitely is worth it to switch back and forth... you'll appreciate riding more... If you're used to picking a straight line and bulling through rock gardens, you simply have to change your riding style a bit. But then again, if you're the type that bombs a ski slope without enjoying the turns, you're likely to be happiest with a FS. But if you like to savor a trail and choose a line the same way you'd pick a line snowboarding through the trees, maybe you should rediscover the feel of a nice, steel hardtail. It's pure, it's simple... it's a little slice of heaven.
My friends all ride FS and they genuinely hate my guts for saying all this... I've been riding MTBs for over 20 years, and I am certain of one thing: You must absolutely love (and be one with) your bike. For me, I love simplicity and mechanical beauty... THAT to me is what makes the perfect mountain bike. Whatever you ride, make sure you love it.
Peace,
MBB