For what it's worth, I prefer to use fairly fast servos and tone down the response around neutral using exponential -- with the JR transmitter, "+12%" on aileron and "+20%" on elevator suits my style.

You can get more speed and power out of your servos by boosting the voltage from 4.8 volts to 6 volts. A 5-cell, 270mah or 300 mah pack is ideal for this. Be aware that it will take longer to fully charge unless you also upgrade your charging system. Also, the current drain will be higher so keep a voltage meter handy (the kind that puts a 200ma load on the system when measuring) and don't fly if it drops below about 5.8 volts.

That being said, I've now gone back to 4-cell packs and things are ka-nuckin' along just fine ... JR 901s or 3021s on elevator and aileron, JR 341s or Hitec 85s on rudder and shutoff.

I prefer nylon gears because they're lighter, smoother, and never get sloppy. Yes, you will wipe them out in a crash, but if you crash a Q40 you'll have a lot of other problems that are 'way more expensive than servo gears!