very nice man! break in process is a never ending debate.
In this case i'm with Ian. When I had Blues' engine rebuilt the shop did all the work and let them tune it with a 'contracted' tuner. He's tuned everything from Subie's Evo's, and much more so he's know.
Mine was a little more extreme with a modified 18G, 100mm bore, all emissions delete including Grimmspeed TGV's and fuel upgrades.
my motor was built, had a safe tune on it and literally sat on the dyno for a break in process.
Oil changed and then it was driven for 500-800 miles to make sure all leaks and nothing else happened.
Only after that did they changed oil again and strapped it to the dyno for a final tune to see what it had and get all the HP they could.
You can't just treat a subaru like a Honda. not the same AT all. I'll admit Subaru's are more senstive but when built right, treated with respect and maintained they are beasts.
sadly mine died in an accident so Ian, best of luck with yours!!!!
ohh and 325hp is very conservative
ive seen less modified WRX's lay down 320awhp.