I must admit that I have not flown an EF Yak, But I have flown an 33% TTTOC Yak, two Aeroworks Yaks, Edges, Sukhoi's and a (35% size) wild hare Giles. I have to say that the Wild Hare Giles is the best plane I have ever flown hands down. I don't fly IMAC, just strictly 3D. Once I got the plane dialed in, I LOVE it. If the 50cc plane flies as good, you would NEVER be sorry. Look close at the wing loading. When I bought the (35% class), I bought it strictly for the wing loading. In 3D it is everything. the Giles lands so slow, you could almost back up and try it again.
Here is a video I took last saturday in the snow
http://www.youtube.com/watch?v=S5h2PxoQYZk