The result was I paid $200 for an FX-8350, which probably wasn't AMD's fastest chip at the time
Maybe not, but close - the FX-8370 is just a slightly better binning of the same part.
I remember all of the benchmarks compared it to the i7, which of course trounced it.
Funny thing about that - there were some pretty major discrepancies at the time between benchmarks done using Intel's compiler and those done using GCC. When using GCC, the FX smoked the i7 - it wasn't until the next generation (or possibly the one after that) that the FX started to lag behind. Even today it's reasonably competitive (if not faster than) against Haswell i5s.
The FX-9590 doesnt seem to be a significant step up in performance from the 8350.
The FX-9590 isn't even a step-up - it's the exact same part, overclocked ridiculously (hence the 220W TDP). It's a stop-gap measure by AMD to try and disguise the fact that the FX line-up hasn't been updated in years.
I'm planning an upgrade myself atm, and as much as I prefer AMD, they're literally a non-option to me (even with the sticker shock from i7 prices). I hope Zen goes well for them, because otherwise Intel has a monopoly on high-end CPUs...