I always liked the 20K attraction at WDW. Although I live close to Disneyland, I feel the theming and setting was superior at the Florida Magic Kingdom. The subs were more interesting, CM outfits better themed than Anaheim. The underwater show effect was about the same though. Both were dated.
However, Disneyland has restored their subs with a Nemo theme.
I don't understand why the MK couldn't have updated their sub show too. The water lagoon was a nice element of that Fantasyland. If cost of operation was the reason, then why is Disneyland able to successfully have a sub attraction????
I understand the former sub lagoon is now a big landscaped area. Even if the 20K theme was to be eliminated, then I think a water based attraction should have replaced it anyway - maybe The Little Mermaid???