Nothing.
Quite spacious for a small car, but the performance, especially the acceleration is worse than other comparable cars. Also it has a lot of body roll and the brakes are far from exceptional. The car also has some annoying rattles and creaks.
I agree with most of your points however I did find your comment on the brakes odd. As a former Mazda mechanic and former owner of a metro I drove a number of metros and the earlier bubble and found the brakes to quite good. In fact mine actually out braked a modified Mitsubishi Lacer turbo from the same speed. It was also used as a motorsport official vehicle and towed a 500kg trailer with few problems with the brakes. I did find however that these cars really are sensitive to dealer brake flushes, mine had one every 20 000 km.
I have heard that some of these 1.3 Metro's have done over 200,000 kilometers with courier companies. Hertz uses them, so they must be pretty good.
Shortly I will be going for my probationary License and I am interesting in purchasing my uncles 1997 Mazda Metro. I have taken it for a test-drive and am more than happy with it. Not only are they affordable…the petrol lasts longer than you can imagine, there have been trips in that car and back to Melbourne twice and to Warrnambool once with only one full tank, and if that not exceptional then what is. I think the other comments, the people must be expecting to much. Its not a car you would buy so much to have the best looking car and do it up, but if you just wanted something reliable to zip around in, cheap and will cost you next to nothing for maintenance I strongly recommend this wonderful car because if you do not expect the best, you will not be left disappointed!!