I've got some wandering and disjointed thoughts about the subject at hand.
I have a couple of medium format film cameras. The one I used the most was my Mamiya 220 Pro F TLR, 6 X 6. It has a waist level finder . I mostly used my heavy duty Leitz Tilt All tripod, when using it.
I also have a Yashica mat 6X6 TLR camera with a waist level finder.
I found that when using my medium format bodies with the waist level finders...it always worked better for me to have the camera mounted on the tripod, where I could adjust and level the cameras. I also found that when using a relatively large and heavy, awkwardly shaped 'box' like the MF...I tended to take my time and compose photographs more carefully....all while the camera was mounted on the tripod. My Mamiya TLR doesn't have an in camera light meter, which also added to the process time. I'd, compose the picture, then take a light meter reading with my separate hand held meter (another time consuming process) , set the aperture and the leaf shutter, then check the composition once again through the finder, focus and trip the shutter. So for me using my Mamiya, there were a few more processes that I had to perform before I could take a picture, compared to my SLR/DSLR. In addition 120/220 film was more expensive and I tended to budget more when using the MF cameras in the film days.
In contrast, I found my SLR bodies with eye finders much easier to use...they are lighter, I can compose quicker, although not always better and I can take pictures much quicker.
Often I think of a quote by the famous British playwright, George Bernard Shaw made about photography, many years ago.
"A photographer is like a cod, which produces a million eggs in order that one may reach maturity."
When I think of the speed that I use, when (sometimes) taking pictures with my SLR/DSLR...compared to how slowly and with care, I generally photograph using my old large, awkward, heavy Mamiya 220 TLR...for some reason this quote comes to mind,
I know the Pentax 645/ Fuji MF digitals are far removed from my Mamiya, but I wonder if people using MF digital bodies, work slower with these larger cameras.
Using a MF, perched on a tripod generally slows me down, oftentimes providing a better image than I would of got with the ease and convenience a smaller, lighter, possibly some may say...more user friendly ASP-C/Full Frame camera body.