CP is absolutely a must do. We did our first Disney Christmas in 2011 (literally, were there for 9 days leading up to Christmas, then drove home the day after). CP was the highlight of the trip for us....it was the event that we most looked forward to, and the one we enjoyed the most.
We saw Trace Adkins in 2011, and did the dining package with dinner at Rose & Crown. Trace was PHENOMENAL.
Last year....early December, DH asked me what I wanted for Christmas so I *jokingly* told him "weekend getaway to WDW just to see CP". Guess what? He did it! We went the following weekend, pulled DD (8YO, 2nd grade) out of school for one day. Lea Solonga was the narrator, and she was incredible!! We were able to get a dining package also on short notice, I was SO relieved, and we ate at Garden Grille.
On Christmas Eve, while I was driving home from work with DD in the backseat (she attended camp that day at the day care my employer has onsite) she said "I wish we could hear the story told in the Candlelight Processional". Hour commute home, searched YouTube for past performances and linked the cell phone up to the car speakers via bluetooth and BAM...cried like a baby all the way home. That story, the way it's told in the CP experience, is very emotional for us. And the music....OMG, the music.....the night before our day in the park this past December, we had dinner on the Boardwalk property and parked behind that Hess station right there at the corner. While walking to our car, the chorus was singing "Hallelujah" and DH and I burst into tears right there in the parking lot.
Already looking into a weekend trip this year too so we can see it. I can see that the CP will be part of our Christmas tradition for years to come.