[lincpimp]

Torque output and ability can be directly related to the rotating portion of the motor, and its diameter. Outrunners cannot rev as high due to their design. However they produce more torque at lower rpm, due to the diameter and pole count.

It all depends what you want. If you need something slow revving with alot of torque then an outrunner is great. If you need a large rpm window, then get an inrunner.

I use quite a few outrunners, but still with transmissions. I have also done a few direct to diff conversions where the outrunner replaces the primary gearing. Those pose problems as well, such as high startup loads, and they generally do not spool up as fast as an inrunner (mainly due to the lack of gear reduction).

For most the normal setup of an inrunner and primary gearing will suit them better. For those of us that like to use outrunners, well, we will continue using them...