I haven't measured it as in degrees per second, but I've flown the 6A, 7A, and I own a 9A.
Below Va, the 9 is very quick - I wouldn't say its just as quick as the 7A but it feels like the other RVs below Va. You can roll a 90 degree left turn to a 90 degree right turn in a blink. And like the other RVs, its like it's on rails - very precise. The 9A stiffens up with speed and it takes a lot of pressure to push the stick to the stops at elevated speeds. In fact, I've not pushed it all the way to the stops above Va.
I'd be curious to know at what speed the comparison of the 12 and 9 roll rates hold true. I tend to think that statement is more of a marketing ploy - to persuade potential customers that it's a 'real RV'.