Calypso.
Hands down (and not just because I own one
)
The Radian is an awesome flyer, but unfortunately adding the flap/aileron servos and flattening the wing really undid many of the things that made the Radian the great plane that it was . . . and Flyzone learned E-flite's lessons.
The Calypso is a great compromise between the two. very stable, very floaty, very powerful and full house + flaps.
I *do* recommend the flaps add-on (really just the servo horns -- add 2 HXT900's and you're done cheap), I do recommend adding an inch to the prop (I've run the stock 9x6, 10x6 and 10x7 . . . and the motor/ESC doesn't mind the bigger prop and climbs like a rocket)
Stock flies beautifully with a 3S 1300. Add a touch of tail weight and it flies nearly *FOREVER* with a 3S 2200.
I **REALLY** recommend adding lights. She makes a *GREAT* night glider . . . I just added them to mine and I can't believe I waited so long to put 'em on.