It seems like two types of MX5 have been around in reviews. For example, BestMotoring mentioned that the MX5 they pitted against the other cars in their lap runs, showed it to be wobbly and difficult to handle, whilst an earlier model they drove, proved quite different.
Some owners of the new MX5 have mentioned the same thing. Either the cars have been a clear improvement over the older model, or they've experienced a driving behaviour well under par.
Talk has been that Mazda is not properly aligning their cars during the building process, and this is resulting in a batch of cars which handle badly.
I still maintain that most reviews have given the MX5 the better score, not just in aesthetics, and the one reviewed by GRMotorsport may have been a defective model.
But who knows for sure *shrug*
It was discussed over here btw:
http://forum.miata.net/vb/showthread.php?t=162545