Having done all of my basic aerobatic training on a Robin 2160 I can safely say that it has enough power and speed to do all that is required to teach you basic aerobatics and more.I've since moved on to flying a Pitts S2A and was the Australian Champion at Sportsman level back in 2001.
My flying school is the Sydney Aerobatic School located in Bankstown NSW. We were at one stage the largest operator of Robin 2160's in the world, with 6 of them online.
We only have 2 left now due to the reduction in people learning to fly due to the costs involved.
You cant go wrong with the Robin 2160
Cheers from Downunder
Brad