If you mean the Plus4SS at £50k against the Plu8+ at £90k, then it's not really a fair fight. If it's the AeroSS at £120k then it's closer.... but I still prefer the back room Roadster.
I suspect the engine deal is still in the air.
DaveW '05 Red Roadster S1 '16 Yellow (Not the only) Narrow AR GDI Plus 4