The NSMB games are fun (even if I'm tepid on the slow starting/stopping speed when running), and they can be a riot with friends. But they do feel almost cynically cheap in their production values. It's like Nintendo thought we wouldn't notice if they recycled a good chunk of the music, or we wouldn't notice how jarring the 3D character models look against the painted 2D backdrops. The WiiU installment would've felt a lot more "special" if they put the same effort into the character models that they put into the backdrops, and if they added more than a few new enemies and world types, and if they put a serious effort into the music rather than coasting off what they had already created.
EAD Tokyo's work, meanwhile, practically sparkles by comparison. The quality and quantity of music tracks, the sheer variety of level types, the relentless level-by-level sense of "this is neat and NEW." They don't sport "New" in the title, but EAD's titles honor that title better than the familiar fare of NSMB ever did. Although perhaps the "New" moniker was never meant to be an indicator of creativity, but rather a simple note to the masses that yes, this is a Mario title like the Mario you remember but a Mario title you haven't played.
On a side note, I was pleasantly surprised by the coin collection element of NSMB2. I don't know what collecting coins accomplishes in the end, if anything, but the act of triggering their appearance and grabbing as many as you can is fun in itself. Not to mention that the level designers did an excellent job of stringing them along in places that guide you to secrets, even secrets within secrets -- something the series has always done, but never to this degree. NSMB2 is the most underrated NSMB title, I'd say.