I've flown both, I own a radical 135 wl of 1.8 and have jumped a cobalt of the same size. radical seems to come in a little faster, so it may be a little steeper. Front riser pressure seemed to be lighter as well. I have been told(could be wrong) that the radical is supposed to be more like the comp cobalt.
Also interested in the radical... Is it just morpheus tech in USA that sells them? I checked the site and there colour picker for the Radical only shows 1 rib inbetween the cells instead of 2 ( making that weird crossbrace looking end cell) .... So is this the same canopy?
Some guy on ebay has 65, 75, 85, and 95 Atair Onyx for $450 each, sounds like a bargain. (I would need to sew three together for my needs)
All Atair USA canopies were purchased in bulk by Bryan Moffet in Texas. He used to compete with Bryan Harrell, Eric Butts and I on the Atiar pro team. If you want a nice, highly-swoopable nine-cell, then buy one of those NOS (new old stock) Cobalts. Amazingly, I just had an old buddy re-gilft me my original Cobalt 85 last week. I'm gonna put it on risers and see how well it fly's. FWIW: they flew exactly like Crossfires.