Rob

I know they are not popular as some seem to have issues with them, I have used the 5955TG's in petrol 3D airframes for years without issue so the 7955's should be better, spec below:

Hitec's best servo just got better. Based on the powerhouse HS-5955TG servo the HS-7955TG has the added benefit of Hitec's G2 second generation programmable digital circuit. This new circuit has twice the resolution of our original circuit while adding programmable overload protection.

The HS-7955TG has been designed for the most demanding hobby applications including the largest aircraft and monster trucks. Featuring a titanic 333oz./in. of torque at 6.0 volts, all this power is harnessed by incorporating the industries first Titanium gears for incredible wear resistance and two strong hardened steel gear pins and axial brass bushing in the servo case.

Hitec HS-7955TG Features

G2 Digital Circuit
Coreless Motor
Dual Ball Bearing Supported Output Shaft
Titanium Gear Train (MK first gear)
Programmable Features

Dead Band Width
Direction of Rotation
Speed of Rotation (slower)
End Points
Neutral Points
Fail Safe On/Off
Fail Safe Point
Resolution* (default is high resolution)
Overload Protection* (default is off)

*these features are only programmable with the HFP-20 field programmer

Mike