Keith, that is a common problem I have at Anthony's, our Friday night series. Multihulls start last, so we have to pick our way thru the big mono's. It always works to tack clear to their windward, than come down to pass.
Yep. The fun starts when you're in a big mono fleet spread out wide and converging on a turning mark. Last year's Oxford/Hammond Memorial races were a great exercise in wind shadow/collision avoidance sailing! On some points of sail the larger racing monos aren't that slow - trying to reel in some of the PHRF A0 boats upwind is an eye opener, as would be trying to catch some of them downwind without a chute.
Bottom line - based on performance alone I'm not sure it's a slam dunk that a stock Hobie-17 would beat the Kiwi big boat in a windward-leeward race. Makes for a fun daydream though...