In my last year of Supra ownership, I bought an S1 Elise as a fun weekend car. Sorry to say but I hardly ever drove the Supra after that (except on long journeys and to the supermarket!)
My S1 had a couple of grand spent on the engine to bring it to 160bhp and it was an amazing car to drive. It broke down about 4 times in the time I had it and it was the most unreliable, badly-built car I've owned. It was totally worth it though
I sold my Supra and the S1 to fund my S2 111S. Again, it's magical to drive - well balanced and really responsive. Mine is the last one with the Rover K-series engine and it's had head gasket failure amongst its many expensive bills. It's much easier to live with than the S1 as an everyday car though - which it what mine is.
The elise isn't for everyone. If you drive it hard (as intended!) and don't mind the cost, unreliability and impracticality then go for it!
my S1 and S2...
http://www.13amp.org/misc/history_s1elise.jpg
http://www.13amp.org/misc/history_s2elise.jpg