The Perimeter Ride is essentially a social ride around the city. I'm not sure if you're asking because you think it might be too fast for you, or too slow for your liking. Either way, it's a strolling-on-your-bike-and-chatting pace. I'd say it comparable to summer CCM pace (when on bikes, not when we have to get off and walk due to a bottleneck).
Hope that answers your question. And please direct any further questions to John Greenfield's Perimeter Ride thread, so we can keep all info on one place.