If the deadrise is the same and the boat has a sharp bow entry then it will probably be as good as you can expect for that size boat. One of the reasons why I kept my old 88 H-200 was the hull design, it has a 21* deadrise and a very sharp bow entry and is excellent for a 20'9" boat in rough water. I take it out in Long Island Sound on calmer days and feel pretty safe given it's a small boat. It can get rough out there because there are some much larger fast moving boats out there from time to time.
The only way to get a better riding boat in that size is to go with salt water designed boats like Dual Console fishing style boats with outboards, they are more designed for big water than typical bowriders and have self bailing decks for more safety. For example a Key West 211 Dual Console with a 200 hp 4 stroke outboard will be the same size but more seaworthy because of the self bailing deck and fully foam filled construction (unsinkable like a Boston Whaler). I see boats like this offshore all the time and yes people do use them for watersports too.
http://www.keywestboatsinc.com/boats/show/id/4