I agree with Andi, some nice photos, but what you are showing currently doesn't really look like it will lend itself well for MF... and "quality" has a lot of implications... like are you able to get those semi-candid shots... also, what size output? Are people putting your work on billboards? No way would I give up a DSRL for what you are currently doing... percieved quality will be more about light and composition.
My stuff might end up on billboards, that is the big issue, I want a camera that if a job comes around that I need the quality, then I have no worries at all, and I don't plan on buying a camera until those type of jobs come around, I just want to be ready when they do. How far can work from a 1ds3 be used? If it had the quality to be put on a billboard, then I might use it. I am a little at odds with myself here.
The differences between these platforms goes so much further than just resolution. I would find a local medium format digital user or dealer and spend some time with the camera to see what it's all about.
