My experience is that (most) spinners give off reliable pre-failure indicators (if you take the time to look/script looking), but SSDs fail by disappearing from the bus. The SSDs do fail much less often, but they still fail from time to time and recovery is harder.
Either way, if your data is important to you/your customers, you really need a backup/recovery plan.
I dunno about recent pricing, but not so long ago, it felt like spinners had a pretty high price floor and SSDs didn't... If you don't need a lot of space, you could find a small SSD that was still around the same $/GB as a medium sized SSD, but for spinners, there's a floor in dollars and space. So if you don't need a lot of space, you save money with an SSD and get better perf for free... If you need a lot of space and not a lot of perf, big spinners are more attainable than big SSDs.