I played all 36 holes last week. I had never been on the property before. I really enjoyed the day. My friend and I both decided that if we were members, we would split our rounds 50/50 between the North and Old. I play a lot of 9 hole rounds and would imagine I would choose the Old back nine more than any other nine (especially in the evening). I thought the back nine on the Old course was fantastic. However, I think the North course contains a stronger 18 holes than the Old course does. I understand TD inherited the routing but I didn't love holes 4-8 on Old course (they aren't bad holes, they just didn't seem to complement the rest of the Old).
On the other hand, all 18 holes on the North course "make sense" and make for a fun, challenging, engaging round.