The most important thing to me is centering and with these servos it's rock solid. Also, before replacing the servos in my 105" SkyWing Edge 540 (NorthwestRC) I would go to do a pop top and it was slow. Now, after replacing the servos with ProModeler brushless servos (DS630BLHV on rudder and DS470BLHV everywhere else), when I do a pop top the model snaps around very fast!
Also, like a lot of guys with these 120cc models, I run two servos on aileron and these ProModeler servos are easy to balance (so they're not fighting each other). I'm just using the balancing capabilities of the radio instead of an amp-meter or balancing box and these servos are really quiet. They have absolutely no buzzing. This is a relief compared to other brand servos that squeal and whine and drive me crazy. Don't you hate that? Anyway, better radios do the balancing for you and I'm glad these servos are very quiet.
After flying them a while, I'm still glad I bought them. This is why I recommend you also get these for your model.