Thanks for the info on the Spider-Man pics. I guess the main thing my wife and I are worried about is that our kids are little and I've seen a lot of opinions that US/IOA is better for bigger kids/teens, and at WDW you have all the "magic." We are not huge Disney people but we did enjoy our 2 trips. Just don't really know what to expect or how it will compare in regards to our kids. I know my wife and I will probably enjoy it more(we both like thrill rides) and I really think the kids like it as much if not better.
I think you'll be fine. It's a lovely hotel; take some time to look around, definitely! At WDW there's "pixie dust" and at Universal it's "mummy dust". The Team Members at Universal are often also Cast Members at WDW, and our own personal experience has been that the TMs are happier and more joyous than the CMs. We've never encountered one that we KNOW works at both, FWIW, so I can't tell you why that has been our experience, but it has.
Since you have the younger kids, you'll go looking for younger kid things! And you'll find them. Let the kids torture you guys with the Barney show, and be SURE to use the EP for the line. Why wait in that line any longer than necessary, LOL. Take them all the way back beyond the Curious George water play area to the ball play area. It's awesome amazing fun with the softest play-balls I've ever felt; you can get pummeled with them from a "gun" above and it doesn't hurt. Follow the footsteps while going through the Curious George section if you don't want to get wet, though!
Kids can go into lines even when they can't ride; you swap out near the seating area, and there's a nice place for the non-riders to wait. If it's a spooky line, like The Mummy, the EP makes it easy enough to swap (unofficially) like you do at WDW, though...both adults end up just using the EP line, no worries. My son is 9 and still won't set foot in the Mummy's line, let alone ride it!
But back to the hotel, it's really pretty. The pool is big and great (and you can pool hop), so I bet you will ALL have a terrific time.