After 3 years of rocking RPM's I can tell you a few things... The 6m 8m and 10m are amazing kites. The 8m is probably my favorite but my best sessions have been on the 10m. They have crap for range and don't handle gusty situations for shit. The kites will flex and crease at the leading edge bridal attachments when they are super lit, its short-lived and harmless. However when theses kites are in a steady situations they're money. When im powered on my 8m there isn't a kite on the water i'm "jealous" not to have. Unhooking is very fun and they excel in the flat-water freestyle uses and the kiteloops are forgiving and graceful. Kite relaunches just ok... for the surf they are good but not great. They tend to pull a little to much when im powered not letting me kickback and surf the wave more, think the rally lets you depower and wing the kite overhead while you surf. The 14m isn't for the surf though, unless you ride South Padre... not around here.
You probably need a big kite for riding inside the bay regardless of the brand/model. Some guy has a 14m RPM on this forum for sale, $600. good deal if the lines are nice, imo.