RE: Extra 300s
The Graupner is a lovely plane, finished very well. The only slight down side is that it is a little on the heavy side. You should be able to loose a little weight by replacing the aluminium undercarriage with a light carbon undercarraige and removing the aluminium control rod guides to the elevator and rudder.
As standard the Extra flys very well and can perform most manouvers. Don't put the CofG too far back otherwise it may be prone to tip stalling, though that is the same for any aircraft of that type.
Hope you get one, they're good fun!
Sarah