If we're just comparing Aladdin's Magic Carpets to Dumbo, then I will definitely go with Aladdin. I love the theming, the much shorter lines, the reuse of the spitting camels from the Aladdin's Royal Caravan Parade, and I don't think they're a waste of prime space. What else are you really going to put right there? And the pathways are plenty wide, so I don't see that as a good argument against them, either.
I'm not saying I dislike Dumbo, though I will admit that it is the ONLY attraction in the four Disney World Parks that I have not been on (unless you also count the Spaceship Earth refurb). I have, however, been on it many times at Disneyland and eventually someday I will force myself to waste 30-50 minutes of precious WDW touring time to go on it at the Magic Kingdom. Are the lines shorter at the after-hours parties like MNSSHP?