I also have it on all the time on hot days. On cool days I don't use it.

 

All great info, thanks for the fast responses. This will make the car more enjoyable for me, I was under the impression that it was somehow bad for the A/C system to use it extensively.

And yes, it seems like recirculation blows harder at lower fan levels. With recirc. on the lowest fan setting with A/C on is sufficient for most California days, but with the recirc. off I seem to need at least two or three lights on the fan controls to cool off the cabin.