For those wondering, the crab is the only repeated boss.
Are you sure about that? I recall that the Area 2 boss returned in Area 5 as well. Am I just misremembering?
Anyways, I just gave the podcast a listen. I'm sad to hear that you guys were so turned off by the game. I personally really enjoy it, and I think it gets better as it goes on. That said, I agree that the game has so many bizarre decisions in it: we've covered the controls already, and the save points were not placed as well as they should have been, but I also have to say that the level design felt really uninspired when compared to the original's. The boss battles also last a bit too long for my taste, although I think the bosses themselves are great overall. The Area 6 and 7 bosses in particular were really cool. And oddly enough, I think this game is much harder than the original.
In the end, I think the game is a worthy follow up to the original Blaster Master, but it also feels like a series of missed opportunities. I would have loved it if they had updated a lot more features; being able to permanently power up your guns a la Metroid, for instance, or perhaps fighting a boss battle inside your tank. Even having more varied backgrounds would have been nice: there is more variety starting with Area 5, but it's sad that the first screen of the game obviously had a ton more attention paid to it than anywhere else. (And for the record, the original took place underground, but there was still a lot of variety between the areas, both in the fore-and-backgrounds. I know someone in the podcast asked that).
So it's a missed opportunity, but I'm still looking forward to seeing what else Sunsoft has up its sleeves.