I had a 55 plate S2k, links to my username - final part of the reg was KMZ which kamikaze suited the car well.
Loved it, but much prefer the Z for day to day. If it was just a weekend car, then I'd be tempted based purely on the drive - but noise, plastic interior & the roof cover just didn't work for me - plus the rear bumper number plate surround seemed to gather rattling stones inside it - those who have had one should remember that fun!
Amazing gearbox & then noise when you are in the mood. Had forgotten the bhp to litre ratio until I reread this. Insurance was much higher than the M though. After reading about how the diff can lock through puddles on one side, I found it a little disconcerting in the wet ; probably a forum fear based on a minority, but still stuck.
Still miss it though, which says how strong the positives & fun of this car are.
DPG - that RNBP was the colour I had, it's gorgeous
Z4MC - wish I had both, like you do