The biggest diference is the way they land. The 4* is a floater that will just settle as light as a feather, while the H9 is more like a carrier landing.[X(] The T-34 takes off better than the 4* and seems to 'groove' better in flight. The 4* is more sensitive to wind mostly because of it's lighter wing loading. They both do nice aerobatics, especially if you add some diferential aileron throw to the T-34.

I haven't flown a 4* in a while and am currently awaiting a good weekend to fly my T-34 after cutting some flaps for it. Get proficient with your 4* and go enjoy the T-34. (Just remember to land faster and a bit steeper)

quint