Area code 612 (Minneapolis) has 7D dialing. Its been quite a while since I've had a land-line, but as far as I remember the last area code split codes (763/952/651) had 7D dialing too (I live in the 763 area, work in 612, the split was geographic, not overlay). So, overall, the splits in Minnesota worked very well overall IMHO.
Back when it happened, everyone I knew could deal with it (even my mom) shortly after the split, it was never a problem in my circle.
But yes, between PBX dial plans, VOIP dial plans and cell-phones, I don't think many even see the opportunity to do a 7D dialing now-a-days.