So far i am seeing no gain over the K03's but that's because i think i have software issues.
i only paid $2K for the K04 upgrade, but i got the turbos's/hardware/software for free. I just paid the installation. (i can't give details on why this was possible)
I added a 4 bar FPR today hoping this would help slightly.....Nope. So much for that band aid. Luckily the APR software didn't get confused.
I have to get the injectors and MAF housing at the minimum + a decent flash.
Unitonics mentioned 390Whp with the above but want somewhere around $800 for the flash. That would make my total bill around $1500 with install.

Issues i'm experiencing:
Only boosts @ 16lbs (Seriously???.....K04's????)
Had to add a "MBC in parallel" from Vast because it would peak @ 25 and send me into Limp everytime i boosted.
3rd gear upwards it surges from 12-16 lbs twice per second. It's like riding a horse. One of the shops recommended replacing my N75....i just don't believe thats the fault....i think it's either fueling or software (or both)

The first 2 days i had my car back with the new turbos it was beautiful....It's like something adapted or broke. it had a lot more power that K03's with none of the above issues....Still only boosted @ 17lbs though