Yeah they're separate, although there's definitely an affiliation there. And IMHO earlier versions of WKO+ didn't really offer anything over TP Premium for most individual users, but WKO+ 4 has a completely new set of metrics not available on any other platform (including TP), so it's worth checking out depending on how serious you are. IMHO the new PD Curve-based metrcis and optimized intervals are especially useful for focusing on above-threshold work.