Bummer that it wasn't what you were hoping for. I get it.
We pretty much only went for the different mood/environment and even moreso for the different parade and fireworks. For us, that alone was worth it. By the time we did our first
MNSSHP in 2013 it was our fourth annual trip to WDW and we needed something different for a change. MNSSHP fit that bill perfectly. We've been back for MNSSHP twice since.
We never did any of the character meet and greets and did very limited trick or treating, so those didn't matter much. It's typically busy, but not packed.
As with most stuff it's all about expectations. We were just hoping there was good weather, since the tickets are non-refundable, and something new/different.
Dan