The Elise has many virtues and has been developed following many philosophies that I readily agree with (lightweight, minimalist, direct handling little sports cars). Value/Fun/Performance for your money they're great.
However, having spent many hours in Elises belonging to friends of mine, I have three reasons why I could never live with an Elise in my driveway. IMO three very important things:
1. The Engine. Yes it does the job (as the performance figures clearly state), but to me the engine is the heart and soul of a car. The Elise has a thoroughly uncharismatic 1.8 Rover engine which sounds like a lawnmower (Although I think in the States it looks like you'll get the variable valve, peaky toyota lump which should spruce things up significantly).
2. The looks. I couldn't live with the fussy 'look at me' lines.
3. Flimsy build quality.
Classic 911 lines, a free breathing, screaming flat six and high quality German racebred engineering. There is no substitute.