Hulk is a really well executed outdoor coaster with an original score, nice surrounding area on the water (minus the backside of PoE) and mild theme-ing.
KEEP IN MIND THIS IS TOTALLY MY OPINION, BUT...
Dragon's Challenge is honestly the weakest coaster in all of Universal, not only that, but probably the weakest non children based attraction (basically not anything WW's Kid Zone or Dr. Suess). It's fun, but the view is rather weak as you can see undecorated areas, buildings that kill a decent chunk of the feeling of the area and just as a whole it feels out of place in the Harry Potter sections. It's not bad, but personally it doesn't feel like it matches up to the quality they're going for and to put a ton of work into decorating a coaster that was never even designed for the land it was in further than they have would probably be a waste.
If there's a ride that has to go, I'd definitely say that's pretty high on the list (between the amount of space it will clear up, it improving one of the most successful lands they own and in general improving the park's quality). I want to make it clear though, I don't hate the ride and this is 100% just how I see it personally.