It is a while since I have flown both of the types you want information on. The Aerobat is capable of flying modest aerobatics - but its rate of climb particularly is pretty weak. Start at 5000 and it does not take long before before you're down at 3000. It is quite a fun machine but nothing to get excited about. Two up it becomes pretty sluggish.
The KCAB is a fair bit better, it is actually built for Americans so it will take two large people - pretty cramped in an Aerobat. The performance is good enough that you can pretty much maintain altitude doing modest aerobatics. It is more expensive and probalby needs more maintenance than the Aerobat - but it is worth it!