I loved my RS when i had it.
I ran it on a budget - was still a student, so things were tight and it wasn't a mint example by any means but it was good enough to use everyday and be complimented on often.
Like you said, its brilliant horsing a knob in a diesel jag just for a laugh, or pushing some poser and his schoolgirl missus in a typeR up the road etc...
However... would i have another one now? Would i fuck! Since then i've had a BMW, not an m5, just a 2.5 but it was comfier, smoother, more reliable - just! just a much nicer place to be imo.
Still miss the fun i had in the rst but not the maintainence or worries i had when driving it, could hop in the beemer and go wherever i want, 400miles away if i wanted and i knew it would be good for it, in the RS i'd probably think twice.
RS Turbo wins for a young, pennyless boy who wants a fast car to drive like its stolen and have great fun in.
BMW wins for reliable, quick, comfy motoring. Pro's and cons of both.