Hei there dude,

Since the server in RCUNIVERSE is down..Will give u a better understanding on 3D and aerobatic planes.
Aerobatics planes are normally scale(CAP232,Extra 300,Giles and so on) or non scale like the Majestic,Spacewalker and so on.THis planes are normally fast and can do most if not all 3D monuevers.But they are a little tricky and snap/stall easily(thats why they are aerobatic u see)You would need more experince to fly one of these and master all their monuevers and need to be CAREFUL.
Lately(not too long a ago) this 3D planes have becme popular.This planes have HUGE control surfaces(elevators and ailerons).They actually look like over grown trainers to me!!Eg. are like the 'U CAN DO 3D', FLIP 3D(which i think is the best) and so many more.THis planes can be flown very slow and are easier to recover once stalled.Doing 3D on them is a breeze(any beginner can do it actually) and is more for fun flying.Doing Harriers and Hovering is actutually much easier once you master it.
You also asked about trainers>Do i really need to explain on that??!!!
Cheers man and hope u got enough info.
>Balakrishna.