I recently brewed 10 gallons of Saison. Split batched and pitched Wyeast 3711 (French Saison) into 5 gallons, and Wyeast 3724 (Belgian SaisonTM) into 5 gallons. After primary fermentation, I split again into 2.5 gallon batches and did 2.5 gallons of each unspiced, and 2.5 gallons of each w Grains of Paradise, Malabar peppercorns, Star Anise, Juniper Berries, and peels of Lemons, Limes, and Grapefruits. The aromas were amazing--I looked forward to depressurizing the corny kegs each day (Used the kegs as secondary fermenters).
The 3711 ferments fast and drops clear (temps 70-74 F); the Wyeast website lists 77-83% attenuation, and low flocculation.
The 3724 ferments slower, gets stuck around SG 1.035, and glacially drifts down (like 0.010 points per week or two) at temps in the mid 70's. It remains cloudy ("mit hefe") and has not dropped clear, yet (and it has been nearly a month). The Wyeast website lists 76-80% attenuation, and low flocculation. Interestingly, it seems to recommend a higher temp range (70-95 F).
Both are good tasting up until bottling. The real test comes in a few weeks when others will judge the beer in competition.
I'll let you know if some miracle has occurred within the bottle.
All other things being equal, I prefer the 3711 since it ferments quickly and drops clear, while the 3724 does not.