Perhaps both of you can't be wrong. How long did you last? Or, how long did you use that combination?
Choosing won't be easy.
I did stick to one film & dev (and only one printing paper and paper dev. too) for a whole year but, after about 7 months of only one camera and lens, I fell off the wagon and shot a few rolls of color neg in the Nikons.
I still shoot probably better than 80% with the Crown Graphic though. I could easily live without the small format gear...and would happily sell it if it were worth anything.
I've recently opened my home to not one but, two 8x10 cameras and so....well, I can't just let 'em sit...they'd feel totally neglected (along with all that lovely 35mm gear). I'll probably still mainly shoot the Crown Graphic though. I cannot see 8x10 having a significant place in my line-up.
Seriously though. I recommend the discipline to anybody. It really does free you from alot of mental anguish...and you really get to know the combo very well.
(caveat: The Crown Graphic is special in as much as it is a hand holdable 4x5. It is the best of both worlds. I could not limit myself to a camera that had to be on legs all the time. I have kids to photograph!)