Do Kevlar Belts really offer puncture protection?
Kevlar fibres do resist cutting, and the kevlar belts in my tyres have certainly stopped lots of sharps (mostly glass and flint).

What it won't protect against are pinch flats (which you can avoid anyway by keeping your tyres at the right pressure) and, if it's just a central belt, it may not protect against sidewall cuts either.

There's generally a tradeoff between ride quality and puncture resistance FWIW: my tyres are lighter and faster than Schwalbe Marathon Plus (for example), but also less tough.

If you want anything more than generalities, you'll need to name those tyres and ask about them specifically.