The 500 is a big scooter. I hope you won't be disappointed, but doubt you will safely get much more than 5000/7000 out of any brand of rear scooter tire on that big bike. Big scooters famously eat rear tires at a prodigious rate. Nature of the beast. Have heard some owners mention going through 2 or 3 rears a year.
I'm running City Grips on my small scooter, and love them. Got 12k on the rear and at 14k the front is still going....but all this on a scooter approx 1/2 the weight of your's. Big scoot = big everything...incl. running $ for tires.
My VW Beetle's radial tires rotted long before they ever wore out the tread. Tall tire, low weight, low HP = long life.
Stig