[solidsleeper]

Any reputable IC coming from the E9X platform shouldn't have any issues with outlet fitment even if it isn't exact OEM spec. I believe Wagner is one of the few to advertise an OEM outlet fit for their EVO 1 Performance model, but this would only really benefit you if you're using the OEM charge pipe (doubt anyone upgrades IC without upgrading CP first). I think most IC will require some trimming of the plastic shrouds, but the EVO 1 shouldn't require any plastic trimming. (I recall one member's post selling the EVO 1 peformance and stated no trimming necessary w/ the E84 M Sport front bumper). I'll probably end up going with the EVO 1 Performance for a daily driven street application.

For the Intercooler outlet to turbo charge pipe, I haven't done enough research to know if it's worth upgrading for a less than 400hp setup. The outlet charge pipe isn't as crucial as the inlet charge pipe that is prone to break.

Supersprint catback is pricey. From what I read about other cars with Supersprint is that it may be too quiet (catback section only) and you're not getting any real hp gains on the X1. I'm curious what the X1 would sound like with the OEM M Sport catback and Supersprint straight midpipes.

900$ is also pricey for a catless DP. I do like that the diameter isn't outrageously big which I'd guess is for a stock turbo setup. I don't exactly know if a larger diameter DP for a daily driven stock turbo setup would benefit or be negatively affected at the low end due to low back pressure (disclaimer I don't have much knowledge other than reading across the other N55/N54 forums). Wagner does make a catless DP with the flex piping, but the diameter might be larger than Supersprint's DP.

Tune-wise, I believe MHD is the least invasive OTS tune. Just need the cable or wifi OBD2 dongle and the android app. I'm stock on MHD stage 1 and I'd give it 4/5 stars for now (it's only been 1 week with MHD so still need more time with it) I'd give the app and it's capabilities a 5/5, but I'm not 100% convinced on the tune and also you can read the MHD thread on the e90 site. If adding a DP, my preference would be a custom tune. In the future I would go with RK Tunes. (Note: I'm biased towards RK Tunes and this requires removing & unlocking of the DME)