I have only been to the Yachtsman once, and this was probably around 2007. The steak was delicious, and along with the additional sides the meal left me stuffed. The only reason I have not gone back is I have since married, and my wife is vegetarian. I'm sure they could offer a vegetarian dish, but I don't eat enough steak to justify going there for a family dinner. However, if steak is your thing it's hard to beat the location, atmosphere, and the food.
Flying Fish is one of our favorite on property restaurants at Disney. Normally I go for their seafood offerings so I can't speak on their steaks, pork, chicken, etc... However, if you're looking for a restaurant that has excellent service & seafood then I highly recommend FF. The chef has always done a creative & inspired vegetarian dish for my DW. The tables aren't necessarily on top of each other, but if the restaurant is busy it can feel "tight". With the recent renovations the dining room is beautiful.
Both locations are priced pretty closely I would believe so it really comes down to what you're in the mood for. The Boardwalk & Beach/Yacht Club location can't be beat for walking back to Epcot for post-dinner strolls.