Just for the record, before my S3 I owned a Focus ST3 (from new so the RS mk2 was not available) which was mapped to 271bhp with 440NM and I have to say there is not really a lot in it between my stage 1 S3 and the ST.
As for the cheap interior it came with Recaros as standard, dual zone as standard, 6 cd Sony HU as standard as well as a few other bits and bobs. The build quality was just as good as the S3 (if not better in some places) and the only reason that I changed cars was because of the release of the RS mk2 (I had to choose between the RS and the S3).
In terms of if being the budget performance Ford then do not forget that before the RS was released the ST was the flagship performance Ford!
One final thing, the 3.2 A3 is nice but lets be honest it is still just an A3 and NOT an S3 (note the letter S
)