If you want a good dual ball-bearing servo at a great price, I have about 10 of these installed in my planes (40 sized) and they work great. They are quick, strong, and quiet, and they center very well. Price is excellent too, especially if you are buying other things from HC like their volt-watch knockoff.

Curtis

[link=http://www.hobbycity.com/hobbycity/store/uh_viewItem.asp?idProduct=3743&Product_Name=HXT_6. 9kg_/_39.2g_/_.16sec_Twin_bearing_servo]HXT5010 BB servo[/link]