Own a GSX R750 and did ~20,000 with the Angel ST. The wear bars are finally showing so I'm swapping them out this season. I did all the thunder storms this summer (sadly), knee dragged ramps, and other hooligan tactics with them on. They also don't explode when attempting top speeds so the Z rating isn't bullcrap (closed course tested of course).
The only downside is that there is an obvious dry grip difference between these and their sporty cousins. Trying to find a road in flat *** Ontario to need sporty tires without going 50 over though was impossible for me last season. Also, as you noted, most sport tires from general census implode around 6,000km and cost around the same. So, imo, Angels all the way!
They also provide better grip than sport tires in cold conditions if you're into that sort of thing lol