I got the Fantasmic dinner package when I went last year (I always visit WDW alone, btw), and I thought it was just great. But then, I'm not one for waiting patiently in line for an hour or hour and a half to snag a seat.
I got the least expensive package, for Hollywood & Vine, and enjoyed the buffet a great deal. Then, about thirty minutes before the show, I went and got my seat.
I thought it was money well spent. But I understand that if it rains and they cancel Fantasmic, you are out of luck and have just bought a really expensive meal...
With all the rain FL has been experiencing, that's a definite factor to take into consideration!