I always recommend booking for the trip rather than the ship. I haven't been on the Wish and my hopes aren't super high for how much I'll like it compared to others BUT I'm sure I will still love it. It doesn't have to be my favorite ship in the fleet for me to have a good time. Personally, I don't think there is a bad
Disney cruise ship. Each has unique features but its not like you go on one and you get a Carnival caliber cruise versus another you get a
DCL caliber cruise. For example, my favorite ship is the Magic but I've sailed on the Dream twice. That doesn't mean I didn't have an amazing time on the Dream.
I have done a couple short cruises and bumped them up to a WDW or universal trip and it was great. Personally, I am all about more days on the cruise but my husband and kids LOVED doing a park too. We opted to rent a car and pay for parking at port then we walked off right away when we could with our luggage and took off to the parks! I did use Uber once, it was a little chaotic finding our uber and I can't imagine trying to do it with a bunch of kids in tow. If you uber book it ahead of time, if you wait until the morning of it'll be 3-4x the cost