We have seen it once - done! Our family has no "need" to see it again. We watch the parades, fireworks and Illuminations again and again, but don't have that same need with Fantasmic.
It's good, but it was truly a hassle to view.
If you are new to WDW, skip it this time. There are so many more great things to do with your evening while in WDW.
If you go to WDW more often, then add it to your list.