It's principal limitation (which is anecdotal--I haven't
experienced it yet) is that the Reeves drive doesn't transmit torque
well at low speed.

You'll have to define what you mean by the above, it is a constant
horse power device.

If you do get it, let me give you a hint for working protocol. You're
not supposed to change speeds without the motor on. Therefore, get in
the habit of turning the speed down every time before you turn it off.

A "Reeves" type drive should be running when you change speeds to
minimize wear on the belt and the sheaves.

You also don't want to leave the drive in one position because you
will tend to wear a groove in the sheaves at one place which makes a
smooth change of speed very difficult.

Lew