As far as if it worth it, the opinions vary. IMO, it was kind of neat to see, but not spectacular. If you are staying at one of the resorts that it passes by and you are at your resort at that time of the evening, I would definitely go to see it. Or if you are visiting one of those resorts at the time...why not? For instance if you are going to Chef Mickeys for dinner, you might hang around to catch EWP. But if seeing the EWP is your only reason to visit the resort and it involves the usual transportation (estimating a minimum of 20 minutes each way), I wouldn't make a special trip to see it. I've seen posts that said the EWP lasts 20 minutes, but I think it was more like 10 minutes.
We saw it on our first night at the world (we did not go to the parks that day). We had planned to go to Ft. Wilderness (we were staying at POR) for the campfire, then watch at least part of the movie and then go to the Ft. Wilderness beach and watch the EWP, but the campfire was rained out. So, instead of hanging around Ft. Wilderness, we went over to the MK resorts and rode the monorail(s), looked around at the resorts for a while, and then went to the beach at the Poly and watched the EWP. We had planned to ride the monorail and see some of the resorts on our trip anyway, so it all worked out.