It's a somewhat different game, but definitely enjoyable. I like that it makes "alliance play" less effective. Of course, alliances and coordination are still possible and necessary, but it takes keen anticipation to be effective.
With any diplomacy variant, it's less fun to play with idiots, but I think gunboat especially requires awareness and understanding of the dynamics of the game, that is, how localized actions affect the entire game. Idiots can often ruin any diplomacy variant (i.e. by setting up another player for an easy win), but I've found that idiots tend to more often get themselves eliminated early in the cutthroat action of a gunboat.
I also like that it takes significantly less time than a press game. You don't have to wait on press or maintain several active conversations. Instead of talking, you just have to infer what other players may want or do based on their previous actions and position. It may seem difficult or silly, but with a good group of rational players, you'd be surprised how effectively they can communicate through their actions and positioning.
I didn't think I would like gunboats so much before I tried them. Frankly, I thought it sounded like a silly concept and that it would just be a bunch of people making random moves (well, the idiots do play gunboat in this style). However, once I played a few games with good players, I realized that this variant is pretty awesome. Goes to show: don't knock it until you try it!
PS: don't overlook the votes! If there's a 12SC power and everyone else but him is voting for a draw, that probably means that they want you to join them in stopping the solo.