flew rv4 today, 10 twenty minute flights . 46fx 11-6 apc prop , c.g. 3-1/2 inchs. very stable airplane, will do standard aerobatics. inverted flight just a touch of down elevator, beautiful knife edge , with full flaps impressive harrier landing . normal landing flaps not required. totally pleased overall . this is not a 60 size airplane. 46 fx perfect engine for this plane. considering price , apperance,and over all quality i would give this plane a 10