I haven't seen the new models, but I have the 65 & 85. The 85 motor seems to run much smoother & faster than the 65. Problem is, it's too heavy to use except when absolutely necessary.
My Husqvarna is my go-to extended hedger, but I've had heaps of problems with it.

Have a Stihl KMA135R kombi head ordered, that might be ok now that it doesn't need to run off a backpack. Might be a while waiting for it though. Been on order since before Xmas.