I have one with a Saito 72. It is definitely not 3D capable. It's too heavy and has puny surfaces. Now that my CG Sukhoi is on-line, the little GP Extra has been relegated to collecting dust. I was never able to groove with it. $.02

I am actually trying some IMAC these days. I'm flying the basic sequence. I go through it four times during a flight and screw off the rest of the time. From my personal experiences, I think you would get very frustrated trying to fly IMAC or any other precision aerobatics with the little GP Extra. It is simply not a straight enough flyer. My opinion is that you need at least 66 inch wing and very light. You want a slow airplane so you have plenty of time to keep your airplane tracking during the sequence. The longer the better too.