Something that customers have mentioned to us a few times is cuts playing back slightly fast or slow. We had a customer recently whose cuts were coming back a little fast despite the strobe sitting steady and pitch locked during cutting.
A turntables strobe on its platter shows you whether speed is consistent, but not necessarily whether that consistent speed is exactly 33.1/3 or 45 RPM. For example a turntable running at a steady 33.5 RPM will show a perfectly stable strobe, but everything you play back will be slightly off.
The best way to check this is with audio rather than a test tone. Cut something with clear transients, a drum hit or anything percussive works well, then record the playback into your DAW and line it up against the original file. If your turntable is running true speed, the transients will stay aligned throughout. If it's running fast or slow, you'll see the playback gradually drifting ahead or behind the original. The further into the recording you get, the more obvious the drift becomes, making subtle pitch issues easy to spot.
Once confirmed, use the turntable pitch slider to dial in the speed. Make small adjustments, cut again, record back, and check the alignment each time until the transients stay locked throughout.
This is worth doing from time to time. A turntable that's slightly off means every cut you do will play back at the wrong speed on a correctly calibrated deck. The transient alignment method doesn't need special equipment, just your DAW and a recording of your cut and saves a tonne of hassle down the line.