I hated limbing with the thing, LOL, you had to hit the trigger about .5 second before hitting the limb, just to get the revs up high enough, but in a big cut you could just pull on it hard and it would just cut right along very nicely.
Sam
My 066BB (NWP from Baileys - i like to call it the 666), seems like it's almost the same as the stock 066 was for acceleration, but seems a bit happier with a slightly slower WOT no load rpm. I haven't tach'd it, but I'd have to say that it pulls the same or better rpms in the wood even with only a couple tanks through it. The BB has a bit more compression than the stocker as well...enough that I use the decomp on cold starts.
Limbing with it (32") is and always was lameballs compared to the 440 with the 28" es light bar...