I don't think Amphibs are that bad, I've never served on one but did an exchange program for a few days. There's usually a rivalry between amphib and CRUDES, and everyone seems to have their preferences. My second tour was staff duty and I worked with two guys who were on amphibs and they both loved the slower lifestyle. Really it's just a matter of preference.
Minesweepers are pretty much universally hated. Yes, you'll probably pin faster, but if you're not a dirtbag you're going to pin anyway. You're probably asking yourself why nobody likes minesweepers, and the answer is that it is a difficult lifestyle, long hours, lots of work, lots of duty (in San Diego they were in 4-section duty. Think about that for a second. 25% of your in-port time is going to be spent on duty, not at home, not at the beach, not with your significant other, etc.). Plus, it's pretty much a thankless job. The minesweep force is almost always overlooked, probably because it isn't "sexy" enough. My friend did his first tour on a sweep and he said the movie "The Caine Mutiny" was the most accurate description of life aboard a sweep. That's not a good thing.