The only data I could find on the JR servos is the newer #527 at .25sec servo speed and 40oz/in torque. I doubt your older #507 is better than that.
The Sanwa 102 is a better servo at .22sec speed and .50oz/in torque.
EDIT:... The Sanwa 102 is basically an Airtronics 94102. Sanwa is the company that actually makes Airtronics radios.
Your in kind of a dilema here. You want the fastest servo on the rudder, which you have now. However, you would also want the strongest servo on the collective. As your 102 is both your fastest and strongest it can't be in both places at the same time.
You didn't say what ship you have. If its a CCPM ship, like the Venture, ( I assume you have a .30 size bird), or a fixed swashplate ship like the Nexus, then I would leave things like you have it. But if you have a "standard" control ship like the Shuttle, Sceadu, or Raptor, then I would replace the 102 to the collective and use one of the 507s on your rudder. I doubt you'll see much difference.
If your flying a .50 size anything, put the 102 on the collective and get some better servos all around. Or, at least some more 102s for the cyclics as soon as you can.
In any case, I would suggest you get a Hitec 525 as soon as you could afford it and put it on the rudder. Its inexpensive, has a ball bearing, is fairly precise, fast, and works perfect with your CSM gyro.
Hope this helps,
Viva La Airtronics!