I don't have a power meter, but I have 15 years of HR and course data. I find having data on past performance is invaluable for assessing and planning. I recently paid TP the $120 to go premium and I'm glad that I did. HRTSS isn't the same as TSS, though in some cases it's better. I've been on Strava for free for a while and recently upgraded to premium. I don't think it was worth it. However for those without a power meter, the combination of free Strava and TP premium is very nice. Did TP correctly predict your collection of Strava PRs? As your CTL and TSB go up do your segment watts increase also? Looking back over the past year's training, I find quite a good correlation, which gives me confidence in TP's algorithms.

A superior thing about TP is that I've been uploading data from my Polar watch to Polar software for 15 years. I use the Polar for my not on-the-road activities: rollers, spin class, weights, hiking, DH and XC skiing, even core workouts. I capture everything, because without everything, CTL and TSB aren't worth much. And TP will upload Polar data through Device Agent. Bingo.

So, an honorable mention for those who collect HR and ride data but can't afford or don't want to bother with a PM. And a question to the PMers: so how do you input the data which I collect with my Polar to get your CTL and TSB?