Ignore the 'too stiff, too impractical" pansies. Honestly, it's a real sports/track no-compromises kinda car... what do you expect? Jeeez. An Elise will run rings round a MX5 or MR2 (which are not performance cars - just fun roofless cars). An S2000 will have to be very will driven to keep up on the road. On track, it has no chance. Never driven a Clio 182 (sadly), but I've passed a few on track!
So just do it. It can be used every day if you are not too old/fat/crippled/wimpy. There are easier cars to live with, but you don't buy a Lotus for its practicality. I've had Elises for 5 years and never found anything to tempt me away. I use mine for commuting every day, even in winter. In summer, I go home the looooooong way round. Then when you add in trackdays, camping trips to remote places, tours of France, Le Mans pilgrimages it's a fantastic tool!
One issue is that there is nowhere in Sheffield that has even the slightest clue about servicing Elises that I've seen. Jude Performance in Newcastle is a good place for the annual service and is only a couple of hours away (just off the A1). Fair prices and they know Elises as well as anyone in the land. Great reputation in the owners' clubs too. If you have a trusted local garage here in Sheffield they can do any in-between niggles, but make sure they know what they are doing with Elises - they are mechanically simple, but unless you are familiar with all the little niggles, they can cost a fortune in replacing bits unnecessarily just to solve a problem. Owners' club forums are your friend for the wee troubles, or PM me. Head gasket failure is nothing to worry about either... whatever the internet experts will tell you. It happens, but usually to heavily modded cars or high milers. £700 absolute max will fix it if it does happen. The Toyota powered models have fewer niggles, but weigh probably another 200kgs, so depends how "pure" you want the driving experience to be.
Running costs are fine. Tax is £200, petrol is about 30mpg (the joys of 750kg cars) dropping to 20mpg if you thrash it (still very good), servicing is £180-300 annually, depending on what needs done. Anything else (sticky tyres, performance mods) is optional, so you only spend if you have the spare cash. Oh, beware: trackdays can be costly and highly addictive!
Basically, go for it and PM me if you want any buying advice.