It's been a while since I read PW's technical report into the HSS issue with PW but my recollection is that the failures of 580EXIIs in HSS mode were a weakness of (some?) 580EXIIs, the weakness turning into failure when they were subjected to the stresses of HSS. I don't think it was an inherent problem with PW's HSS in particular, and I'm guessing it's possible that other makers' triggers would present 580EXIIs with the same risk in HSS mode. I'm happy to be corrected on this, if anyone cares to read PW's report again.
Other than that, I think my positive views about the YN-622s have already been stated often enough. I'm using four of them.