I did not like an adj. travel fork on my FS bike. I really like one on my hardtail. the one I'm running now goes up to 150mm ( and the bike came with an 80mm fork). I like the slacker geometry on decents.
You should have no real issues going from 80 to 100 on your bike. A better fork will make you rides much more fun.
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Like a circus monkey on a stolen Harley......