Since I have chimed in.

If you have all this work done get out and abuse the car and find out what is/isn't happening and maybe tune it from there.

There's no point spending uber dollars on shit if you don't actually need it.

Hit up no limits nights, rac days, skid pans, collie days and anything you can get into.

Seat Time will more than make up the difference in times/enjoyment over a sub rear frame ball locking diff cradling device.

If you want proof check out the rallysprint results :-) compare Jamie listers time to most other wrx's and see where his awesomely balanced version 6 is placed compared to the others.

__________________
2016 Subaru Outback - Work Wagon
350NM of CVT Goodness
Pit Crew, shit talker.