They are actually fairly similar and I took to the Pro One right away. My Rad Pros have a 340 SW and are very stable but I found the stability of the Pro One to be comparable. I felt like I can apply a bit more spin with the Rad Pros but not enough of a difference that it would scare me away from the Pro One (and can probably be explained by my string setup). One difference that stood out was the flex of the racquets. While I like a soft racquet and have had wrist tendinitis issues in the past, the stiffer feel of the Pro One did not present a problem and I felt like I had better directional control over my current racquets. The biggest difference between the two was the feel on off center shots, they just felt more solid with the Pro One. Less vibration and shock. I think Donnay has a winner on their hands and this just went on my very short consideration list for replacement racquets for my Rad Pros (the other being Volkl PB10 Mid).
(4) Volkl PB 10 Mids
Babolat Tonic+ 16/Babolat RPM Team 17 @ 51 lbs