just wondering about those setting up by restoring on the 12.9".
I've always been set up as new kind of fella based on what I have read and see but not sure if it truly makes a difference.
Probably doesn't matter in the grand scheme of things. The last couple devices I setup as new. Especially my iPhone, which I was restoring since the original iPhone. I have found less errant behaviour when setting up as new. But can't say for certain the clean setup was the reason.
These days my philosophy across all my devices (computers included) is to keep up with major and minor OS updates, but new hardware gets a clean install. For me it's not a big deal because I use configuration profiles to setup a lot of stuff and I also have very few third-party apps.