Check this thread out on the Chipmunk

http://www.rcuniverse.com/forum/m_22...tm.htm#2223570

Its a great flying plane and I feel the Supersportster will be a 'lesser' plane. I wish I could get one here but the sales of the Chippie is for US only. You may not want a gasser for the Chippie as the colwing may need to be butchered.

The Chipmunk is a slim plane with a narrow fuse (compared with Extras, Sukhois and YAKs) and the SS may be much fatter, hence more drag (increased wing area too of 300 sq in)