I also run a ton of three wire. My panel looks verrry pretty. It has alternating colors red-black-red-black. The only sitiuation is for GFI breakers and arc faults. Which brings up a ? I heard from a fellow electrician that you could share a nuetral with arc's. I told him that I never heard that before and went on my way.

What do you guys think about multiple sub panels? Are they cost effective? What size subs do you run for $4k sq/ft homes?