I think even in your Dynasty I prefer Hilton over Watkins. Who the hell knows when or if the Bills ever get a decent QB and if Watkins will be anything more than a "should have been". Luck is in for a long career as an elite QB, and once Wayne heads out to pasture, Hilton has a better than average chance of becoming elite himself.
I'd rather have Hilton. The Bills haven't had a decent quarterback since Jim Kelly so they obviously don't learn well from their mistakes much like our Dolphins since Dan Marino. It's not like Hilton is old either so you aren't really gaining that many years in the future for Watkins either. Plus, if it's close I always take the guy playing in a dome over the guy in cold weather.