Yes, I think the sirocco isn't a real competitor to the M3RS because of the differential and I think because of the tradition of Renault Sport chassis.... but the design of the sirocco is very beautiful !
For the 235/35R19, I'm agree with you, it's really expensive ! The 18' is more reasonnable.... but for me it's not a problem, I can choose 19 inch tires, because I don't pay it...
Normally in comfort Renault have really work on it and they said us that the cup chassis associated to 19 inch is as confortable as the actual R26.... wait and see !
![Wink ;-)](./images/smilies/icon_wink.gif)