RE: Hitec 5645 servos, Are they good servos?
X-Jet
Excellent explanation of how a servo works, I have a 645 on the rudder of my 82" gas Extra and its works, 4" servo arm and turnbuckles rods on both sides of the rudder so its a true push pull system, I do not notice any cerntering problems at all, and I use 5955's on my bigger stuff, the only difference I can notice in flight is the speed of operation, what more can I say.
Futaba: difficult to get discount on high end servo's although very good quality.
JR: don't want to swap out gears at the end of every season.
Hitec: 5955's for $89 at Troybuilt models, I am from the UK and buy from TBM, price can not be matched in the UK.
On smaller stuff,
Hitec 645 for rudder and 625's for the other surface's
Futaba 3152 good quality fast strong servo.
All the above is IMO and has worked for me.
Mike