FX series gets way too much hate and there are hyped up cherry-picked benchmarks of G3258 and i3s in dual-threaded games that get plastered all over the forums to downplay FX's competitiveness in well-threaded modern benchmarks.
While at this time I would choose an i5/i7 for my overall system build, the FX9000 series is still a very decent CPU performance wise for multi-threaded apps that's brought down by its high power usage and outdated AM3+ features set. If AMD is able to release a next gen CPU with 20-30% faster IPC on 16-20nm node, it will make great strides in capitalizing on its multi-threaded performance.
Considering how old the Bulldozer architecture is vs. Haswell, how inferior the node is that AMD is using for its CPU fabrication, and how little R&D and engineering resources AMD has, what they've done even be in a discussion of multi-threaded performance is nothing short of remarkable. Hopefully AMD can adopt a more modern node with its next 2016 architecture so that we get much needed competition in the $200+ CPU space. AMD also desperately needs to update its I/O chipset features set to M.2 32Gb/sec and by 2016 I would hope PCIe 4.0.