You may just have the wrong camera. Any 6x7 camera is big for handheld use - I didn't say impossible, but you're not going to forget you are carrying it. And the RB, with it's revolving back, is sized more like a 7x7 camera would be, by necessity.

I'd suggest if you like squarish and think the 6x6 might suit that a 6x6 camera is likely to be far more hand holdable and agreeable for that kind of shooting, probably out of proportion to the seeming actual size difference. I've considered getting an RB system myself, but to use instead of my 4x5 to get around the hassles and costs of sheet film. Used like a 4x5 it's capable of almost the same quality, albeit without movements (except for shift lenses which are expensive and still don't have nearly the movements of even my Tech III.) I've never been tempted by it as a handheld camera. I have a 645 Pro and, while it's a great camera, it hasn't supplanted much 35mm as I expected it to because even it is just too darned big and cumbersome much of the time. My Yashicamat 124, OTOH, is a joy to walk around and shoot with, but that gives up the interchangeable lenses and film backs.

If you really want to make MF fun to shoot handheld and don't want a rangefinder, a Rollei or Yashica or other fixed lens TLR is really sweet, but you will be stuck with one lens and no interchangeable backs though.