About 75% of the sports around here have full suspensions, I know I do. I rode both for a while but eventually sold my hardtail and bought a second dualy. I can just maintain momentum much better on the full suspension than I can on the hardtail, even on climbs. Not only that my dually is not much heavier than most hardtails since it only weighs 22 pounds so that is not really an issue. I get a lot less fatigue racing the dually as well, to me that really comes into play on the longer, rougher races.
Some people still love their hardtails. Heck, I love riding a hardtail, just not for racing.
Oh yeah, keep in mind I'm an old man (31) racing in WV. We don't have too many smooth races around here.
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I may be fat but I'm slow enough to make up for it.