I just saw a brand new 4*40 fly this weekend with an OS52FS in it. No mods were made to it, flying on a grass runway. Very nice plane, the pilot says it is one of the easier ARF planes to assemble and fly. You will really enjoy this bird. Just watch the control throws. My friend is says it is jumpy on high rates, and therefore has turned down to 55% on low rates. Now that is very jumpy!

Luke[8D]

P.S. It flies much like the sportster, only I think the 4* has a little more maneuverability to it due to the different airfoil. Good stability even in moderately windy conditions.