You gotta be careful deleting from the camera, sometimes they don't look as good on the 3" display, but they are much better once you get them off to a PC. Granted, I'll delete something that is clearly blurred, but otherwise, I leave the culling work to the PC session.It almost seems like keepers per hour, vs keepers per shot - 2 hours out with film, 2 (sorta) keepers. 1 hour out with digital, one keeper.
Problem with the small card route is you can always delete, and also preview exactly what your shots look like. I'm not disciplined enough to shoot digital like film and I don't even know if I'd want to. There are things about the digital experience that I don't find as appealing as film, but there are advantages that balance them out.