FYI regarding the Gravel King line... expect them to all measure about 3mm more than stated width. I'm running a 700x35 GK+ on my front wheel and a 700X35 SS+ on the rear. Both tires measure 38mm wide at pressure. I don't have enough miles on them yet, so I can't comment about longevity. However, I really like this setup so far. I ride mostly on tarmac, but on the limited amount of light gravel and sand that I've encountered the tires have performed well.
As for the Maxxis Velocita, I've not used that model specifically; but I've used several models of Maxxis tires and they have all performed extremely well.