I recently read a comparison article in C&D or Motor Trend (don't recall) between the M3, RS5, C63, and Cayman.
I'm paraphrasing, but the article identified these vehicles as being in the performance for dollar sweet spot. Spend any less and you'll get less of a car, spend more and you'll face diminishing returns on your money. Sums up my feelings on the M3 perfectly.
I've been fortunate enough to experience some of the world's best cars on track, but most often I'm with an old friend who drives a 130k mile E36 M3, and my brother with an R8 V10.
The R8 is an incredible machine, but with every experience I don't emerge green with envy. On the flipside, the old E36 M3 has so much god damn charm it's ridiculous. It feels light, poised, balanced, the engine is still sweet.
Point is, we all have an equally good time. If you're talking about the joy of driving, "pure driving" as Ayrton said, then I don't find supercars to be markedly more enjoyable than M3s or similar in any driving environment.
Plus, the M3 is superior to most supercars in the majority of driving circumstances. Some (emphasis on some) supercars tip the scale in their favor on a dynamic/performance basis, but the gap is probably not as significant from the driver's seat as most would imagine (or as the price disparity would indicate). And that gap is not enough to negate all of the other advantages offered by the M3. Money being no object, I can honestly say that from a driver's standpoint choosing the M3 over a number of exotics makes perfect sense.
Supercars certainly have their appeal, but I think most who fantasize and posit them as an altogether different and superior driving
experience are mistaken.
DISCLAIMER: I have not driven a 458 Italia