A lot of truth in what Tom has said above, both on the comparison between si and M, and the roadster as a proposition in comparison to the coupe.
My entry into coupe ownership is a little different as I bought a Cat D repaired car as it was literally what I could afford at the time. I do tend to keep my cars a long time anyway, but the si still has the record - kept it for 5 years, did 60k miles and a load of trackdays in it. I still remember picking it up - I simply couldn't believe that I owned such a beautiful car (in my eyes at least). I still have very fond memories and would 100% own an Si coupe again if the opportunity arose.
I did always have an itch for an M Coupe, and finally got mine after 5 years of si ownership - I moved house and found myself with a garage in which to keep a weekend toy. I don't think I'd have been able to justify the man maths required to get an M if I was dailying it, but yeah never stopped me wanting one!
I completely agree with Tom when he said the Si Coupe is 80% of the car for less than 50% the buying and running costs - it's absolutely true. Even discounting the bork factor of the S54 (rod bearings, vanos, cams and follower wear etc), the servicing and parts costs are much higher than the si, and in my opinion aside from the noise and the additional power, it's actually quite a difficult one to justify on paper the extra costs for the experience you get on the road most of the time. On longer journeys in the M (I'll whisper this) I actually miss my old Si - it had by FAR the better road manners, it was softer comfier and the engine was more tractable, albeit at the cost of the fireworks at the top end with the S54 in the M.
I'll hold my hand up in saying I've never done the roadster thing, but having recently been passenger in my mates boxster with the roof down, I have started to understand the appeal of open top motoring. To me the driving dynamics have always been most important, as well as the looks (sorry but to my eye at least the Coupe is miles better looking than the Roadie!), but can absolutely understand (and would appreciate myself) the enjoyment to be derived from chucking the roof down and going for a drive in the sunshine on a scenic road etc. I'm sure one day I'll cave and get a Roadie, but it will never replace the Coupe, that would always have to stay!
I do find the comments regarding the Coupe cabin being claustrophobic interesting - my si coupe had red leather which I rather liked in a silver car - the M has black with the carbon leather effect trim, and black bucket seats etc - sure it's a bit 'black on black on black' in there, but I really like how snug the cabin feels - feels like you're an actual part of the car which to me is part of the appeal!
Anyway, enough witterings from me, glad you're enjoying the car OP, glad it's got under your skin as it has with so many of us - hope you have many enjoyable miles to come in yours!!
I'll leave you with a pic of mine from Donington in April - how can anyone not love that shape eh?!
