Where does it say the seats are optional? I bet they will be I cannot see it.
Looks wise there is no comparison with the R the CS looks the part, the R is just too bland and 4 pipes don't make it look it sporty.
The bucket seats are a optional extra in Germany, it's up to VW UK if the make it standard, looks wise I prefer the GTI/CS in some respects over the R, but for the overall package I preferred the R over the CS hence why I went the R route. I have a feeling the CS will be priced around £1000-1500 less than the Golf R which isn't enough in my opinion.
The Golf R offers better performance and traction for not much more money vs CS.
The CS is for the hardcore GTI loyalists who don't want the top model Golf.