They are both the shiznit, The avid tends to be more I want to bite NOW so whether you want to or not you're stopping. Where as the hopes like, I'm calm I'll slow you down but if you want me to I'll stop dead.
Overall the avid tends to be an aggressive biter
and the Hopes laid back but works if you want it to.
I know that I haven't helped in the slightest, but hey.
By the way I prefer the hope, I'm running old mini at the mo, doesn't bite well but for some reason I can make it work, even though no-one else can.