I had a Super Tiger 90 in mine, inverted with stock OS style muffler and it hauled butt...
These plane takes a bunch of nose weight so use horse power instead of lead.
My friend fly's one with a 61 two stroke and more than satisfactory.
The landing gear works great for an ARF and you need to use a good retract servo, the only thing that I and everyone else hates about the plane is that damn ugly canopy.

P.S. This plane is a vertual copy of the Top Flite Gold Edition Spitfire.