Been raving about the new formula 97s (got the Delfino 55s) here before. Been riding them indoors for the winter and they are hella nice on slippery plywood and dusty concrete. Fast, not slipping out easily, breaks into slide nicely, barks good.
Just adding to my earlier posts that yeah, they do work great in smooth concrete bowls as well. Tried them at my local yesterday and they were fast and grippy. Thing of notice, though, was that they seemed surprisingly quiet. Been riding the Bones X97s a lot lately and they seem much louder and harder than the new duro Spits in my experience. Anyway, as per which ones are faster -- the Spits might have a bit of an edge. They have this weird combination of feeling kinda soft but being hella fast.
Oh yeah, referring to above regarding "the best wheels ever", currently my top 3 in no particular order is:
Spitfire new duro 97 Radials
Bones X97 v5
Bones X99 v5
Jah bless wheel evolution of late. We're blessed.