I had Sidi Vertebra boots for years.
Swapped to the Vortice 2 years ago and been very pleased. Lunched the S1000 at Silverstone in March and walked away with negligible damage to boots and not a bruise or a mark on my spindly feet. Every time I put them on, I feel like my feet have considerable protection.
I tried Alpinestars in the shop, but found the Sidis much more comfortable.
A few anecdotes:
1. The toe area is slightly thicker than the Vertebra. On my Suzuki, I managed to knock the bike into neutral a couple of times as I must have been just nudging the gearshift. I fitted adjustable footrests shortly after, so that was never really an issue.
2. Until you get used to them the ratchet mechanisms mean 5 minutes work to get them on. Even after a couple of years, I'm still last out into the pit lane on track days.
3. The overlap of the clamshell can snag on the heel guard. This is potentially more my riding style than anything else, as it only happens on the right - but it can be disconcerting when you need to move your foot position quickly on the track.