One of the recurring "downsides" I see mentioned by steel boatbuilders is needing to sand (or media)-blast the interior of the craft after construction and before coating/insulating. I can understand this from a logical sense, but it’s hard to imagine exactly what that would be like.
Dirty Jobs is a Discovery Channel show featuring Mike Rowe who goes around the country (world?) and performs various "dirty" jobs. It’s often quite interesting and covers many different cleaning, construction and animal life type jobs that have to be done, but most of us are very glad that somebody else does them.
Anyway, an episode that I saw tonight (Reef Ball Maker) had Mike sandblasting the inside of large metal "frag" or "frac" tanks (used in the oil industry). It very graphically showed just how "messy" and undesirable it would be to be in an enclosed area while you are blasting.
I’m sure some of you could speak from experience, but in some ways this gives a glimpse why epoxy might not be so bad (although I’m still not sure :-)).