We have almost no WDW traditions, but a meal at CP has become one - we've eaten there every trip DW and I have been on except this past April when we were doing low budget/no TS.
As far as food, we think both are quite good, and we are with the PP in thinking most buffet breakfasts are boring and there breakfast is better than most. However, we do love the lunch / dinner food there, so if I was going to pick solely based on food, I would pick lunch. It is our favorite character buffet food - with Tusker House Lunch being our favorite food with no character.
Honestly, you can't go too wrong with either. However, when we did this in December with an 8:05 AM ressie, we were done eating, but had NOT seen all the characters by the time rope drop arrived at 9 AM. We didn't get out of the restaurant until 9:15 AM...though it was our last day and we had to leave the park at 10 AM, so we didn't care so much about rope drop. So while I hear people like eating there and then doing rope drop, be aware you may feel very rushed trying to do this, and the last thing I want to do paying $25+ PP for a meal is to feel rushed. (This is NOT the restaurant rushing you, I am talking about if you feel that self-imposed need for rope drop.)