Trying to understand Sweet Spot

No, I don’t see it that way. Formal testing (= something objective) and verification informed by feel (= subjective) form a feedback loop. Testing allows you to explore what being in certain power zones feel like. And that improved feeling makes estimates for your FTP and other zone boundaries more accurate. I’ve gotten a lot better at pacing since getting a power meter and threshold testing.

That’s why IMHO the FTP/CP algorithm or test protocol don’t matter much, as long as you verify the results.

I reckon even more people pay for TP with first-gen concepts such as CTL and TSS. WKO’s strength is analysis, although when I tried it, I felt it was way too much for me, I didn’t even know what metrics are relevant to me. (That’s where a human coach could help.)

Agreed.
After all, they both attempt to identify the same physiological state in slightly different ways. So in my mind they are practically equivalent.

Someone in here (honestly don’t remember who, perhaps it was @WindWarrior, but I could be wrong) posted their FTP estimates and estimated CP, and surprise, surprise, they were a few W apart (+/- 2 %).

Yeah, in the analysis department WKO5 is the one to beat. However, I think you need to be an expert or be guided by an expert to really know what metrics are relevant for you. I found that WKO did not really help me here, but perhaps it is just not the tool for me at this stage (even though I feel it should be given my background).

Also, maybe I didn’t get that far, but I really did not notice their special sauce (= their model, which I now know has been (co-?)developed by @The_Cog). E. g. I’d rather rely on a FTP test + verification than on SmartFTP. It was purely the analysis features that made it stand out for me.