GravelKing SK 'Plus' worth the extra 40g over standrd SK?
 

Panaracer makes a reinforced 'Plus' version of the GK SK's now. While the standard 35mm SK has a listed nominal weight of 380g, the Plus version is 420g. I've read of people using the standard version for races like DK200 without issues, so how much need is there for the extra reinforcement over the standard tire?

Anecdote and small sample size alert, but since I've used both versions (albeit in the slick model), I figure it might be useful to relay my experience.

After getting a few punctures on my tubeless Gravelking slicks, I swapped to the puncture resistant version and almost immediately got a flat from glass. I was using tubes, so maybe tubeless would have rolled over the glass without an issue, and maybe it was just a rash of bad luck, but I don't think they're appreciably tougher than the normal version tire. I rode the same stretch on Conti 4-Seasons for years without many flats, and would switch back if they were available in > 32mm width.

I don't know if the SK would change the math, my guess is that it's probably a similar layer of protection in the SK and the slick, compared to the normal versions of each. If you can find them for the same price, sure, the tiny weight increase is probably worth it, but if puncture protection is a concern where you ride you might want to consider another tire entirely.

The Panaracer tires I had cut easily with glass.
I like Conti and Vittoria.

curious as to which conti's and vittoria's? thanks

Don't remember which version I had but the sidewall is pretty weak. 3 punctures in the side wall I think one was glass, the other 2 looked like a snake bite but I couldn't figure out how it happened at the time. I rode the same route as with other tires and these are the only ones that had sidewall problems. I was able to plug the tire the first time I kept riding with the plugged tire but after the second set of punctures no more, time to try another brand.