I just ordered a Samsung 256gb SSD for $200 (the reviews on newegg were great). I will use the WD black 500gb as my backup. Is it really true that you can just shut the pc down at any time without risking losing data? How can that be? Is it because of the lack of moving parts?
It's not true on any of the ones I've used, cutting the power while it's in the middle of a write operation is as dangerous as ever and if the OS hasn't flushed to disk you'll still lose data.
You still need caching logic to address the 'problem' of frequent small writes (something which flash isn't really suitable for, because you have to erase an entire block at a time)
Boot times are faster, not instant, but tbh if you're running a dedicated box stripped of services without the usual Windows install/uninstall churn problem your PC will probably be spending more time on the bios screen than booting Windows anyway.
I'll say it again, a top end CPU is far more important for emulation if you're budgeting things up (I can't believe people here are saying AMD is good, but you really need an SSD, that's pretty much the opposite of good advice)