At first, shooting 8x10 and larger slowed me down by the way of the number of photographs I was creating. However, now that I've made it exclusively my only camera that I use, I've really loosened up with it and now photograph ALOT more. There comes a point where the gear no longer should slow you down from creating. The cost of film should not even cross your mind when going to make a photograph. The reason is, with every picture you make, you learn something new and even if it's a bad picture, you will have learned something from making that picture to apply to the next one you make that will be better. Make as many photographs as possible, because it will only make you better.
Now I'm not saying that I'm not really selective about what I photograph, but using the 8x10 has really let me see just all the millions of photographs that are all around us, wherever you are!
The only reason a camera should slow you down is because your spending more time LOOKING at the ground glass, and not more time messing with the gear and equiptment. With that in mind, you should be making just as many pictures with the bigger camera as you are with the smaller ones if your time spent is with looking. If you are not, then there is something slowing you down that should not be.