Or is there a strength/protection/product life thing too?
Steel bead 2.35 super tackies are about 150g heavier per tyre. I'll be keeping those for DH trails in Europe next year.
...and you cant fold them up and put them in your pocket!
is weight the only difference between kevlar and steel?
Nope, ones got Kevlar in it, and the other has Steel wire in it... Can't remember which one has which though... 🙄
I just didn't want to pay for a small weight difference - if they're stronger, or last longer as well, then that appeals. The multitude of tyre options/discussions confuses me a little, and I just want a decent new set for the winter that will work on most anything without costing 50 quid each.
Kevlar is meant to be stronger, however steel is strong enough so stronger isn't that important IMO. Kevlar doesn't stretch though, which is important for tubeless, and may be an advantage for downhilling on low pressures even with tubes if you want to keep your tyre on the rim.
Quite often (not always though), the kevlar version will have a finer (higher tpi count) carcass than the wire version which should give better rolling resistance. In the past, on some brands this has been very noticeable.