Just swapped out my stock ECU for one flashed by Kyle @ ZZPerformance. Not a HUGE difference, but enough subtle ones that I’m pleased: rock-solid idle @ 1K RPMs, a smoother-sounding engine, noticeable performance gains (I can now break traction in 3rd gear, even with my Bridgestone 295 RE-71 in the back!), and a bit more growlier exhaust note.
Will be monitoring MPGs to see if anything changes and will report back.