Turbulence-

Other servos to consider (I'll be using in my Roo):

Hitec HS-5645MG
Speed: 0.18 sec/60 degrees at 6.0v
Torque: 164.2 oz/in at 6v
Length: 1.59" (40.6mm)
Width: 0.77" (19.8mm)
Height: 1.48" (37.8mm)
Weight: 2.11oz (60g)

or

Hitec HS-5945MG
Speed: 0.13 sec/60 degrees at 6.0v
Torque: 180.53 oz/in at 6.0v (11.4 kg/cm)
Length: 1.55" (39.4mm)
Width: 0.78" (20mm)
Height: 1.48" (37.8mm)
Weight: 1.97oz (56g)