"Worth it" is too subjective to really advise someone one way or the other.
When we did it a few years ago, I assumed we would be "one and done". I was glad we did it, otherwise I would always be considering doing it, or wishing I did it. The desserts are very good and there is excellent variety, but I agree, there's no way you're eating your money's worth in desserts alone. A big chunk of your cost has to be considered for the "environment" - meaning, getting off your feet for a bit and not having to fight the masses for a view of the fireworks.
We ended up doing it again ealier this year solely because my parents actually joined us on the trip (something we assumed would never happen). So, to get them a place to sit down and escape the crowds, we decided to do it. One unfortunate thing this time around was that a few years ago, they had a photopass photographer in there taking pictures (great for us as we always pre-purchase the unlimited photo package - DW is a picture nut). They no longer have a photographer in there. We found that disappointing, and something that decreased the value of the experience, at least for us.