Unless you are buying a motor with a TurboDyno print out the numbers are pretty worthless as they don't show the amp draw at max power and max efficiency. Max RPM is also completely worthless. So two motors might both show Max power of 64 Watts ... one might be doing it at 32 amps and the other at 35 amps. The one doing it at 32 amps would be the faster motor. The efficiency number is the same ... it could be 54% at 12 amps or 20 amps. I believe TeamB00d and EA both send motors with the TurboDyno printout. Look for high efficiency numbers in the 20-35 amp range. Don't worry about RPM or Torque - you can always change the gear ratio to get what you need. Now, I'm not saying tuners that use other dyno's don't sell good motors or spend a lot of time and effort on them. You can get some information from the Fantom dyno in the time-base mode ... I don't think it is as repeatable as the TurboDyno but it is better than nothing.
I have seen direct correlation with TurboDyno numbers and performance ... especially at the velodrome tracks.