Keith... thank you for sharing your experiences.
Yes, I may find that I use more movements than I expect to. I just don't recall using that much a zillion years ago when shooting 4x5 but, as you stated, the longer format will likely increase the need for corrections. So... 4x10 continues to look more appealing for my needs.
Regarding film for 5x12: I know I can use the 5" Kodak aerial B&W pan film (Jim Galli does and I'm assuming you do) and I'm pretty sure the color neg film will work too. I believe that stuff has no orange backing which might actually make scanning easier though this would likely cause serious problems trying to print conventionally. However, since I intend to always print digitally (please forgive my blaspheny, fellow APUGers) this isn't a problem. I've posted inquiries about the aerial color neg film but no one seems to have used it for pictorial imagery.