There are a lot of different reviews about it. I thought it was pretty fun! Yeah the fireworks and parade got cancelled, but ride lines were still short. Also I was able to put my focus on the treat trails and a rare character (Constance Hatchaway). I didn't want to leave, even though I was getting drenched lol The hard part was having to walk all the way to Mickey and Friends because the trams stopped running due to the lightning. That's when I got completely soaked. I'm happy I checked the weather and brought an umbrella and jacket.
This happened to me on a Sunday a few years ago. It pounded rain all day and I got drenched. Did it suck? Sure. But lines for virtually every ride were super short. The park ended up closing several hours early because of the light attendance. I was wearing three layers up top and still my T-shirt got completely soaked. It was fun in a way. But also a challenge.