I had an Elise (S2 111S, highly modified) before the Z4M, and I would (mainly) echo what others have said - a truly fantastic driver's car, a scalpel compared to the mallet of the Z4.
However, they really do come alive on track. Depending on which exact car you get, then normal bumpy roads, with traffic calming and potholes and manhole covers can be a pain.
Mine was very low, with Nitron suspension, stiff springs, LSD, CR gearbox, no interior comforts, no stereo, windy windy windows, no air con etc.. I would carefully plan routes to avoid sleeping policemen.
Regarding suspension although it is true that it needs a fair bit of care, it isn't all that expensive - a full refresh of my Nitrons with service, re-valve-ing to latest spec., several new parts, etc.. was about £800. And they turned them round in less than a week.
Generally I found parts and servicing pretty cheap. Brakes are fabulously cheap - they last forever!
In the end I sold mine because I found it too draining on long journeys - e.g. to the 'ring or Spa.
