I wonder why so many are talking about SSD vs. HDD in this discussion. From my experience on Linux it doesn't really matter if you have enough RAM. Yes, booting from a SSD is faster, but once everything is loaded the system mostly works on top of the RAM (waiting for FS sync is rare).
I don't know much about the situation on Windows but at least on linux your HDD is hardly going to cause lags if you have a well configured hardware setup.
I don't know much about the situation on Windows but at least on linux your HDD is hardly going to cause lags if you have a well configured hardware setup.