|: : I don't think inlines are faster.
: I think they are faster in a 200 km race. But not in a half pipe. I did see some inline skaters doing really high airs, but they had chests like rowers. High airs on inlines seems to be primarily a muscle thing.
**If inlines are faster on flat ground, why would they be slower on vert?
As to barrel chest, I would say that it is more likely due to practice. Watch this video for some high airs :