You could also ask Is Disney worth the $$$? Totally subjective. I have been twice, first time was for free with a CM cousin. The skies opened up right as Santa was coming down main street, CM standing ankle deep in water, Santa had an umbrella, etc. It was awesome...we had front row in front of the flagpole facing the castle. If I had paid for that party, I would have been upset.
Last year, we did our last big WDW trip before moving to Seattle...so we were going to do it all...CRT, searaycers, and MVMCP. We were a group of 6, and we had fun, but my inlaws were less festive...which I understood, their dogs were barking after a day in the parks. We enjoyed the photo ops, and special little things scattered throughout the parks (didn't do characters). Favorite this time were the pirate musicians, complete with handbells. Very talented and entertaining.
If you are on the fence, I suggest waiting until a day or two before the party to buy the tickets. I wouldn't go if the weather looks bad or if it was close to selling out. It is fun, but not a must-do. If you only have tickets for 4 days in the parks, then it is a great way to add another fun-filled afternoon/evening!