Hi,
No precise equivalents to be honest, and different brands have different equivalent performances....but...as a very rough guide...
Sensored motors are typical in 10th scale, and offer better control at low speeds/revs as the sensor knows where the rotor is inside at all times, and the esc adjusts timing accordingly to keep the response smooth.
Sensorless doesn't have that feedback, so low speed control/revs is not as smooth/controlled, and 'cogging' was common on the early ones (basically a stuttering effect of the motor not being about to spin up very well from stopped/low speeds). The latest breeds are much better though, and a lot of 10th scale newbies/club racers use them to good effect. Sensorless is pretty much standard and common place in micro (1/18th& 1/16th scale) racing.
In terms of numbers of turns...
10.5t sensored was/is considered roughly a 19t brushed, although 17.5t might be closer to that these days as brushless/esc technologies have developed! They are good for getting started if your new or very green.
For the more practiced, in 4wd 6.5/7.5 turn sensored motors are pretty much the way to go, and for 2wd's 7.5/8.5 are the norm.
With Lipo power the way it is, anything quicker than that is unnecessary for the typical indoor/outdoor track.
I see your in Newport...our Caldicot Club runs every Friday night, not sure if you've popped along yet...or fancy it? Many people to talk to and much to see every week if you looking for some friendly advice and a club to race at.
Check out
www.caldicotrcracers.co.uk or our thread in the club section on here if you don't already know about us!
Hope it helps a little!