The 1.6 Miata Engine is based on the 323GTX (or AWD rally fame) motor, IIRC.
The Miata may be a car for old gay men and college girls, but when you are smoking Mustang GTs and Hondas, it's all the more sweet.
If you want the Miata to look less "gay", there is always Garage Vary to help you out:
http://www.vary.co.jp/wd.html
The Miata is more of the "light weight for all around performance" school of design, while the Rotary cars, although light, are more of the "supercar to hang with the big boys" design approach. Both cars hold tremendous performance potential, but IMO I would have to give the Miata the edge as a non-track only car for it's use of standardized technology and it's tuning philosophy.
Hope this helps!