Hello to the LF crowd.

I have a question regarding LF 4x5 vs. a MF 6x7. I am going to be moving up to a larger format at some point, and I'm debating how far to go. I have shot 6x4.5 and 6x7 MF before, and I have to admit the tonality blows my 35mm prints out the water. I have never shot LF before...is it really that hard?
No, it's not all that difficult. Mostly it's just different.
At what point (i.e. size of enlargement) would you consider MF to be at the end of its rope, and LF taking over?
I think most film is good for about 8-10x enlargement, regardless of format.
Should I consider larger MF, such as 6x8 or 6x9, or just go straight to LF 4x5?
Now that's the question isn't it? I haven't seen (doesn't mean it's not there) on this thread some of the information you need to know about this.
Primarily, 35mm and MF are similar types of photography. The film plane and lens plane are in general locked together. Hand holding the camera is more or less easy. There are many automatic functions on the cameras from metering to autofocus.
When you get to LF, nearly all that stuff is gone. It's really not very hand holdable (even so-called press cameras are big heavy affairs). With non-press cameras you will always use a tripod. You therefore can no longer stick the camera up to your face and "compose with your feet." Instead you'll be walking the scene without the camera, learning to see without a camera up to your face. You'll find the correct perspective for the photograph first, then set up your camera on that spot. Just about exactly opposite of how it's generally done with smaller formats.
There's no pentaprism -- when you look through the lens you'll see everything upside down and backwards. You'll get used to this, but it takes some practice.
The lens plane can be manipulated separately from the film plane with a view camera. Learning how to use movements (tilt, swing, rise/fall, shifts) isn't that hard but does make you think.
You'll use a separate light meter and have to make all the decisions on how to expose the film on your own. No automatic systems to help you with that. But that's why we have things like the Zone System -- to help you make sense of exposure, etc.
Film comes in sheets. Film holders have to be kept scrupulously clean. And you load/unload them in complete darkness.
But mostly it's the far slower, more contemplative method of working that sets the view camera off from the smaller formats.
I'm just saying that it's not solely about film size. It's a completely different ball game. I've never had such fun with photography. I'll never go back to any of the smaller formats. But just because I love it doesn't mean that you will. So consider all of it, not just film size, when you make your decision.