I test drove an ST3 and a ST2 before buying my ST1. The Recaro seats were comfortable enough but not more comfortable than the ST1 seats. The thing I didn't like about them was there was no wiggle room (as it should be for a racing seat) which I figured would become uncomfortable on long trips. Based on the number of folks starting to complain about the lack of long distance comfort my concern has been shown to be well founded. The other thing I found that even with the Recaro seat all the way down I was bumping my head getting out of the car because the side bolster was so high.
I have no plans to participate in track days so I don't need the extra side support. The basic Sync system in our 12 Focus does everything I want. I don't listen to much music so the standard stereo is fine. It just didn't make sense for me to purchase a ST2 or ST3.