If you already have an everyday car then I don't see why not. The Mk2 (NB) is a bit more comfortable as regards suspension and will probably
feel less "jarring" than a Mk1 (NA). Having said that, a Mk1 with standard suspension is not back breaker once it's suspension components
are in good condition.
They are not the most frugal cars as regards fuel consumption (the Mk1 at least) but I guess we don't buy them for fuel efficiency but more
for the driving spirit/fun. Mine averages around 30 mpg. Perhaps a little more on the long steady run.
Spares availability is fantastic for these cars so obtaining any parts required should be a very easy. Robert (Autocheck) on here is great for
used spares. For the "flashy bits" (!), there's the like of MX-5 Parts in the UK.
Reliability is generally very good if you buy a good one. The engines give very few problems. Things like electric window mechanisms can
give out and check for rust issues (sills/arches on Mk1's), especially if the car has come via the UK. The original vinyl on the roofs are prone
to shrinkage but a lot of these cars have had their original hoods replaced by now.
If you do decide to go looking for one, avoid the 1.6 vs 1.8 debate and just buy on condition and buy the best you can. Both engine sizes
are perfectly fine.
Overall, they are great cars and for smiles per €€€ they are unbeatable ! Especially at current prices. I'm on my third MX5 and I've owned
my current 1.6 Mk1 for many years now. I don't think I could be without one !!