For what it's worth, I have the i7 with 395x and a SSD. I've only heard the fans kick in once, when I was doing a four-way video chat and the processor was consistently pegged around 30-50% (still not sure why that happened; I repeated the same thing today and the processor usage was much lower, fans didn't kick in at all). Granted, everyone has different sensitivities to their computer's sounds; I tend to think I'm on the more sensitive side, but that disclaimer is worthwhile anyway.
I chose the 395x for a few reasons, but the big one probably comes down to the fact that the added money wouldn't have been a huge strain on me and I would not have forgiven myself if I experienced slowdowns. At least this way I can know that it's a limitation of the hardware/software, and not due to my own choice. My goal is also to keep the computer for a long time and, futile though it may be, I also wanted to "future-proof" as much as possible.
If you can afford it, just do it. I've now seen multiple statements about heat concerns with the 395x, but I'm not sure where they're coming from. Has someone released temperature data indicating that it's hotter? The fan rarely kicks in (and I am occasionally gaming) and the casing doesn't feel warm to me whenever I touch it... and I'm in the tropics, where it's consistently been in the low 80˚F range which should put even more strain on thermal management.