I have 3 17.5 motors. A duo2, a duo3 and a tekin redline. I use the duo3 most of the time. All of them are very close to the same speed though with similar boost settings. I've seen a ton of different motors perform near identically in 17.5 boosted class. Novak Ballistic, ORCA, SPv3.0, LRP X12, all of the various Trinity/EPIC Duo line of motors, Tekin, Murfdogg, etc., etc., etc.
I think the choice of ESC and the way you set it up makes a bigger difference than the motor does. Lately it seems to matter less and less which ESC you choose though. Most of them have come out with firmware updates now that make them very competitive.
More important than either of these things though is having the ability to consistently drive the best lines through the infield. That mainly comes down to chassis setup and most of all, the nut behind the wheel.
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