Got the components installed today and thought I would give an update. Ill start with my comments on the base stereo and go from there. GLenn C did the install, and did a hell of a job. Sub didnt quite fit under the seat, so he had to do some modifications and handled it with no problems.
1) Base Stereo- rating 3/10. From what I have heard in other cars, the base STI stereo is definitely on the lowest end of the scale, what you would expect from a cheap econo box. Volume is decent enough, but clarity is garbage, base is limited, and it almost hurts your ears to listen to at above average volumes. Found myself sticking to podcasts ect... because I hated the way music sounded. After tons of research on EQ settings, I was able to get it tolerable, but not enjoyable.
2) Base Stereo with Kicker Speakers and tweeters - Barely an upgrade in sound quality. Tweeters add some high end, but the sound quality almost seems worse. Like the low powered head unit struggles even more to drive a higher quality speaker. Rating 3.5/10
3) Alpine Power Pack Addition- definitely fixes the quality of the sound, not sure how it would affect the stock speakers, but with the kicker speakers I am now listening to an exceptionally better sounding system. Total volume hasn't increased much, but that wasn't the issue. The clarity of the sound is much better, and no longer grating to listen to. This in itself would be an almost acceptable upgrade. Rating 5/10
4) Rockford 8" underseat Sub- Definitely the icing on the cake. This took the system and made it sound like a decent factory sound system. Nothing that will shake the car or blow people away, but bass that is evenly matched to the speakers and completely fills out the sound in the car. This is definitely not up to snuff with a Harmon Kardon, or Bang Olufsen or any other premium car sound system. But it is definitely a great sounding stereo, and makes music quite enjoyable to listen to. System sounds great up to barely tolerable volumes. Make no mistake though, this sub does not kick you in the assay, it fills out the sound nicely, but does not make for a punchy system. This isn't a blow your mind stereo upgrade, but for $500 in parts it is highly worth the upgrade. Overall rating 7/10