If I use a tripod with a my 6X7 and truly compose an image in the view finder it takes nearly the same time as with the 4X5 or 8X10. If I hap-harzardly compose an image, letting it float in the finder hoping to crop it in the darkroom it takes less time. Unfortunately I lose that time when I get in the darkroom and try to remember what it was I was trying to capture.
For me it is the "seeing" that takes the time, regardless of format.