The Galleon is competitive, but Heavy guns do need some variety so ships other than the Galleon can have some fun as well, especially the Goldfish, seeing as how the heavy gun is what you will be using 99.5% of the time on it.
I'd like to see a Heavy Flamer at some point in any shape or form, or a giant howitzer.. dunno.
Oh and the Tesla guns, why don't have such guns already?