Three years ago I bought a used mountain bike. The saddle hurt so much I immediately bought a bigger padded saddle and it was fine. I rode quite a bit that summer, but none last summer as I spent the summer overseas. This year I gave my mountain bike to my 22 yr. old son, put the original seat back on it and kept the padded seat just in case. I bought a Trek FX 7.3 with, what looked like, one of those skinny little seats again. The guy at the local bike store told me I might be surprised, and, even at my size, I might like the new seat. That was 3 weeks and over 500K ago and I've not had any issues with the saddle. When I get to, about, 10K, I have to get up off the seat a bit, but that's all. The day I did 100K, the last 25K was sore on the ole' sit bones, but that seemed to be more an issue with the butt muscles getting tired. When I was done, I didn't hurt, and I felt fine the next day. The new seat is better than the bigger padded seat, which, by the way, has been given to a friend with an old mountain bike.
Another thing, my riding, so far, has been without riding shorts. I've been riding in swimming trunks so far.
I think I may have been lucky, but a good fit can do wonders.
John