x-king tire size

[quattrings]

Last year I put on some 2.2 x-king tires, regular ones with steel wire bead.
They are great tires all-round, but they are showing signs of wear and I'd like to get the racesport version next. Also the wire bead tires are heavy.
Most people say you should size up to get the same volume tire. Is this difference also present between a regular wire bead 2.2 x-king and a 2.2 racesport version?

Also what kind of reliability will the racesport provide? I've never flatted the normal x-king, but I'm somewhat concerned with durability of the Racesport. Is it worth it to go with the protection folding tire?
I'm planing on running the racesport with supersonic tubes.