My limit is 2 a day, whether they be deep air or trimix, especially if I plan on diving the next day. I'd consider reducing it to 1 and multiple non-decompression dives if I was looking at more than 2 days of diving. But I tend to be diving cold water, with all of the attendant gear, and I'm as concerned about managing fatigue and the beating that I seem to take from repetitive dives.