In the DC region, they are consistently slower than the CRXs, but still get top-5 finishes. And there are still quite a few that run the series.
If you find one at the right price, it's a great starter car. If you are trying to win, buy a CRX, Integra, or 240.
Or, look to Spec RX-7 or IT-7 (similar concepts, varies by region). In DC we have about 50 Spec RX-7s (average 35+ per race).
The Miata is also a good choice. More competitive in ITA. Also Spec Miata is growing quickly in many regions. The car will be more expensive to obtain, but probably will be a bit more reliable. Great brakes on the car too.