The French is weird because Chatrier and Court 1 are some of the slowest clay courts in tour, but Suzanne is faster for no apparent reason (that I'm aware of, anyway), and is actually pretty nippy by clay court standards. However, given all the important matches take place on Chatrier, overall the French is pretty damn slow. In terms of speed, the major clay events are something like:
Monte Carlo
The French Open
Rome
From slowest to fastest. We don't know what Madrid will be like given it's been extensively resurfaced this year. Could be a surprise. Wish it changed to Hartru, it's a shame there isn't a green Clay Masters given the history of green clay and the sport.