Best bet is to look at Eastrax website
http://www.easupertrax.co.uk/
Ben, the grip is good but varies from corner to corner depending on the way the astro is laid, so one corner you understeer the next it may snatch. As for tyres like MattW has said Schumacher yellows in the dry, I never managed to get stagger ribs to work so tended to just cut the outer spikes off if theres to much , and Ballistic greens in the damp / wet.
As for the jumps, if your sensible they are fine, all I am going to say is use the downslope, thats what it's there for
