60 minutes always. I want a good massage first, followed by a good playful release. 30 minutes is just too rushed and the $ difference is not that much
Now there is an idea - I can save thousands and thousands of dollars...
Seriously, 45 minutes should be the 'bare' minimum with an hour as ideal. The only place that I consider 30 minutes as acceptable is at studio acqua with their morning specials for us busy executives with some spare time on our hands between meetings.