Well, the only problem I ever have with Ness is the fact that I can't properly control PK Thunder with the 3DS controls
And I'm mostly a 3DS peasant, only getting acess to a Wii U when I go my friend's.
It's difficult and makes me a sad sheep. ( I ended up falling off the stage multiple times already because it went in direction not desired, Welp.)
The Wii U controller is so much better, though,(I still fail sometimes, though haha) so I see that as the 3DS controls being bad.
I actually like how Ness works in general.
Using Ness's PK Fire like I use Robin's Arcfire (Stun with it+combo) is working well so far, though I haven't played with Ness as much as I play with Robin. Heck it seems to work better with Ness than Robin, because Ness has some good combos, imo. (And they are pretty too! All sparkly and stuff
)