I understand people's mileage may vary with these kind of things, but it honestly hurt my hand trying to contort my hand in a way to hold the 3DS in a sturdy way while playing the game, and I don't even have big hands.
That was true for me also. I have owned a 3DS for years now, and only while playing Uprising have my hands actually physically ached. It truly was an awful control scheme.
For me Uprising marked the low point in what had at that point become a trend, with Nintendo (and their affiliates) insisting upon control schemes which, in my opinion, detrimentally affected the games or for which superior alternatives existed. As someone who usually held other game creators up to the standard that Nintendo had set, the triad of DKCR, Metroid: Other M, and Kid Icarus: Uprising was pretty disheartening. In the cases of the former I think the games were of a high enough quality to overcome the control quirks, but I can't say the same for latter.