Without a doubt, the STI was one of the WORST cars I have ever owned. Horrible build quality. Dealer could never get the hatch to close right. The hoodscoop and headlights rattled and vibrated at highway speeds. The dash developed rattles and squeaks and made the interior sound like it was falling apart. Horrible gearbox. Syncros never seemed to mesh, clutch was inconsistent and shifter would always hang-up between gears. GPS was old, outdated, cumbersome and inaccurate. Radio was grossly underpowered. Had to be run at full volume to overcome highway noise. Performance is underwhelming - all hype. Sorry Subaru, not feeling the "love"! Didn't last 5K miles with me. VERY disappointed.
Overall build quality could be VASTLY improved. Paint is of horrible quality and is way too thin. The slightest brush with a rock leaves a gaping wound in the paint. Transmission sucks - feels like it's out of a concrete truck. All-wheel drive is nice, but is a big power sucker. Underwhelming performance - thought the car was supposed to be fast! Cheap interior - all plastic and no sound deading at all. Put in a decent stereo for crying out loud! I'd expect this kind of audio quality from a Yugo. Ditch the GPS - it sucks and uses CD's - really? Too many stupid nonsensical lights and displays. Thought I liked the styling at first, but then saw it for what it was...looks like a computer mouse.
As an ex 2004 STi (first year they brough over to the US market) I agree on some of the things you mentioned, but not all.
The paint does suck.
I can't comment on the NAV, since in 2004 we didn't even get a radio and I went with a Pioneer AVIC system that served me really well.
The gearbox is actually pretty durable and so was the clutch. I wonder if they made any significant changes since 2006, but my 04 was pretty mechanically solid.
The weak link in the engine was the oil pickup tube, which I replaced out of pocket as well.
The car is very loud and transmits a lot of road noise, and overall was not very comfortable, I agree on that.
It is after all, a very performance oriented car. I did not use mine as a daily driver.
You should check out the Lexus ISF, very different performance car, but a lot more comfortable. (RWD, V8)