I used to own one of these, not sure I'd wholeheartedly reccomend one though, had a real love-hate relationship with it!
The good bits are light weight, ride, handling, steering and brakes. Proper mid engined handling, you won't find better this side of an Elise (I've driven an exige by comparison) but very friendly with it. Mild understeer if pushed hard, but unlike a lot of mid engine cars, you can hang the tail out a little on the exit without ending up in the ditch. It rides quite well too, I'm drivng an NB MX5 1.8 RS now and it's not as compliant over bumpy roads.
Depending on spec, these can weigh less than 1000kg so feels lively enough off the line despite the weedy 138bhp engine, which sounds curse word and doesn't feel particularly special, though adding a TTE/Remus exhaust does improve things.
The steering is great, it's extremely light, but if you're tuned into its subtlety it provides quite accurate and detailed feedback. Does tend to follow cambers in the road, but not a problem if you're awake.
The cabin is comfortable and spacious, plain and functional but very pleasant, great driving position, more room than an MX5.
Standard brakes are great, at least on road. Overall, it's massive fun and hugely under rated as a drivers car.
..but now the bad.
The horror stories you hear about premature engine wear are absolutely true and not entirely down to the precat thing either. The pre-cat issue is merely something that aggravates an underlying issue with the engine design of these cars. Sometimes the pre-cats do break up of their own accord, but mine failed without any evidence of pre-cat breakdown.
Toyota specified the 1zz engine with under-sized piston rings to enable easy break in. Unfortunately this can lead on some cars, to excessive oil consumption, cylider liner breakdown and engine failure. To aggravate things further, this can contribute to pre-cat wear, which causes engine wear, creating a vicious circle. You'll hear a lot of contradictory stories on the internet, because it's not a simple issue, but rather, an overall design flaw of the 1zz short block that was corrected around 2002/2003.
My advice is either to not buy pre-2003, or get one that's already had an engine rebuild with new liners/piston rings, etc. or had its short block replaced (available exchange re-con from toyota for about €3k, I'm in the republic of Ireland so can't tell you the sterling cost, check locally)
I also had to have the gearbox rebuilt later, but this is probably not typical of these cars. It gave me the opportunity to fit a proper TRD 1.5 way LSD which makes the car even more fun, which brings me to another thing to be aware of, UK vs. JDM spec. UK cars tend to be better specced, with a Torsen LSD as standard not all JDM cars did, especially early models. Bear in ming though that a Torsen LSD never locks, just redistributes torque, it does a pretty good job but a proper mechanical LSD is better so I wouldn't stress too much over having a JDM spec car with an open diff. Even with an open diff, there is lots of traction, and you can always add a superior aftermarket item.
It also lacks much in the way of storage space, cubbyholes behind the seats but they are so utterly awkward to use as to be completely useless. Also, if you have a puncture, there is a space saver in the front, but nowhere to put the full size wheel other than in the passenger seat, it won't fit where the space saver normally lives. These sort of impracticalities get a little tedious in something that is supposed to be an everyday roadster, I'd forgive it in something more hardcore like an Elise or Caterham, but these things are just daft. An MX5 is much easier to live with.
To summarise, it's a bit different, loadsa fun, but potential engine issues and impracticality means that unless you are absolutely dead set on having a mid-engined car, there is nothing to reccomend it over an MX5. It's not significantly faster, it's harder to live with and there's less aftermarket/tuning support.
Some pics (sorry they're a bit small)...
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