Hello,
First post but just had to say something when i saw this.
I had an evo 8 (was a 260 remapped to 350bhp )just before i got the Z. Performance wise it was amazing and i loved the car. Servicing is 4500 miles and costs way too much. Especially when it needs the big service and the engine has to come out etc. I used it as an everyday car (same as i use the Z) and though it never failed to make me smile, i did feel that it was just a money pit (it seemed to spend more time in the garage getting bits done than driving it)which took some of the enjoyment out of it. I know many people dont keep up the service schedules however if you dont then things will go wrong. Just my personal experience but the Z feels a lot more indestructible (probably in my head though lol).
Anyway to cut a long story short, for me the running costs were way too high compared with the Z.
The evo does make you feel like a driving god in some respects however its only because it compensates for my lack of driving talent. For sheer enjoyment i do prefer the Z, though everyone is different.
Anyway good luck with your choice