I'll see if Hi-Fi World can get a simple A-B wow and flutter measurement made on a stock SL1200 vs. Timestep SL1200, soon.

I must say though that measured performance (MP) is only half the story; we regularly test things that measure very well but audition poorly. It's reductive to say that if there's no difference in MP, there's no difference in sound. All that shows is that the MP regime isn't perfect. And it isn't; it's a useful tool, a convenient shortcut, but you still need to use your ears in the final instance. Piano, chewy bass guitar or steel string guitar arpeggios are brilliant at telling you everything you need to know about a deck's wow and flutter.