I had a Z3M roadster and it was fun on a straight road in the dry......not sure about its handling in the wet on the bends, though that could just be my lack of talent,(especially compared to what Tiff does to one in the film Burning Rubber http://www.youtube.com/watch?v=sPC1ZAPo09Y ).
Had a Scooby wrx sti that could get over the Bournemouth Asda roundabout in the wet quite well (the whole thing is tilting on some kind of camber) but had to really slow down in the much less forgiving Z3M.
Had a MK2 Elise with the K engine that was sooo different due to its lightness (CC would have liked it I'm sure) about 300Kgs lighter I think....in the Z3m I looked down on people in their MX5 (the Mk1 of which I very much recommend) then the MX5 would look down on those in the Elise. The Elise is a very low car and offers a totally different driving experience to the Z3/Z4 cars, much lighter and more responsive, maybe more of a drivers car?
I think if you test drive a Lotus Elise and you should if you have never driven one before! you will quickly know if its the car for you, but if you like it you will be back to the "which one is right for me?" conundrum, due to the variations.
PS its the somewhat flawed cars that I have owned that seem to have a place in my heart more than those which were technically better....so yeah my Z3M and Cerbera I feel more emotionally attached to than Subaru's and Audi's etc....