I started racing before there were FS bikes. My first front suspension was a noodle of a fork that I put on my Bridgestone MB4, never really realized how bad it was till I bought my first C-dale. What a difference. Then I was dealing with elasomer sponge springs till I got my first Air oil, Oh My the improvement (especially for my 6'4" 200lbs)
Then I got the Super V active, built it up with XTR stuff and life was good.. Loved the full suspension.
Gettin to the point here. One week I had the Super V down for maintenance (at 200 lbs I destroy drivetrains that are designed for 145lb riders). I'd long since gotten my old Delta V frame back from the shop and built it up with and XT setup so I took it out for a turn on my favorite loop. My word, how different, where is my FS bike, I want it back now!
If all you are going to do is climb then get a hard tail, but if you are ever going to get into the big ring, get the FS.