OK, I've heard the advice to replace the head unit from numerous sources. The Shaker head has the capabilities I need, though. I don't want navigation or a touch screen. The iPod interface capabilities of the Shaker are sufficient. I don't know the last time I used a CD for anything other than ripping into iTunes, so the "skipper" attributes won't be noticed.
Is the sound quality from a $200 head unit noticeable better than the shaker? Realizing that a $200 head unit also needs another $65 PAC C2R-FRD1 and a non-trivial amount of extra work to get installed. Or, is that adapter even needed? The 08 GT doesn't have steering wheel controls, so the ONLY thing a replacement head unit offers is better sound quality. Does it really do that?