This spring I've tried Dragons, X97's and 99a Formula Fours.
The X97's are pretty impressive actually, and are A LOT smoother than F4's on rough ground while still feeling like a hard wheel. I don't find F4's enjoyable to cruise on, but I've used the X97's to take the dog for a walk a few times and they were pretty good. They roll way faster than spits on asphalt. They're actually almost as good as the Dragons on crust, but don't feel as rubbery and slow in a smooth park. Biggest downside to Dragons is how slow and rubbery they feel in transition and smooth park. Mind you there was a guy at my local the other day absolutely killing it on Dragons, so yeah...
I still like F4's better for skatepark, and they just sound and feel like skateboarding to me, but the X97's are damn good. If all your spots are crusty but you still want a "hard" wheel, absolutely recommend trying them. They're a bit more rubbery feeling than spits but nothing like Dragons. Between the three, they sound more like F4's but absorb crust more like Dragons.
Only weird thing is that Dragons actually slide better, both on smooth concrete and asphalt. They still have a good slide, just thought that was odd.