I got one of the first sets of PSS in 2012 and started extoling their virtues to anyone who'd listen. I've got my staunch GT-R owning, ex-Aston test-driver, Toyo-loving spanner-monkey to try them and he's hooked. Every e34 M5 owner I've spoken to who's tried them cannot understand how they can perform so well yet last as long as they do. Even exdos was not convinced that the PSS would be much better than the OE Continentals, but I think he's changed his mind somewhat
In performance terms:
- the PS3 is somewhere between the old Pilot Exalto and the old PS2 - i.e. a 'touring' tyre - something akin to the original Conti M3s the Z4Ms were supplied with (not terrible, but there is better)
- the PSS is somewhere between the old PS2 and the Pilot Sport Cup - i.e. a 'performance' tyre
In longevity terms:
- the PS3 is better than the Pilot Exalto, whilst giving more grip
- the PSS is better than the PS2/Conti SC M3 (10,000 vs 18,000 miles from the rears & double that for the fronts in my experience - including track days & ring trips) whilst giving more grip
The PSS is available in 255/40/r18, but I've stuck with the 265/40r18 as it makes my speedo more accurate.
The other tyres might have a 'BMW-star' on them, but the PSS is supplied OE on the new M5/M6s, so I'd assume they were 'BMW approved' too.