Finally managed to play the 3DS smash, and here are my Samus impressions:
Jab: Yeah pretty bad. which is a shame, because I think the animation looks a bit cooler than previous versions.
Ftilt: trying to implement this more, a bit awkward for me with the circle pad. I think it works better than Brawl's, overall. Looking forward to using the GC controller.
Dtilt: Sorta bummed it's not a kill move anymore, but I like that it's a combo starter into Fair and Uair. Seems like a relatively safe move, haven't been punished for it very much.
Utilt: Doesn't seem as fast as Melee's Utilt, but I've gotten some solid KO's with it, and it seems easier to land than in Brawl
Fsmash: Eh, pretty good. I like it better than Brawl's version, seems to kill much more reliably and has better range, but still easily punishable
Dsmash: Not super impressed. I've used it a couple times to punish roll-spammers, but there seems to be other good options. If anyone has some uses for Dsmash, I'm open to advice.
Usmash: looked pretty good in the trailers, but I've rarely used it, and it still seems pretty hard to land all the hits. Maybe I'm just bad at finding opportunities to land it?
Nair: I actually really like it. Definitely not as good as the Melee Nair, and I miss lasting-hitbox Nair, but I've gotten a decent amount of gimps and edgeguards with nair. A lot of times, it knocks opponents away at a semi-spike angle, which was a nice surprise
Fair: Yeah this is pretty solid. Easy to combo into, easy to land all the hits.
Bair: Good kill move, kinda hard to sweetspot, but it seems a bit stronger than the Brawl version.
Uair: another solid aerial, I find myself using Fair more, but I never used Uair much before, so maybe I just need to get in the habit of using it more.
Dair: Yeah a bit weird with the sourspot, but I hit with the sweetspot 95% of the time, so I rarely notice a difference compared to Brawl's version. When I do hit with the sourspot, it's usually over land, so I haven't gotten punished, but still an odd change.
Zair: I like the multiple hitboxes, but it seems a bit shorter than the Brawl and PM versions. Not sure how I feel about it yet.
Neutral B: Yes much improved. Probably my #1 or #2 killing move. Much better than Brawls
Side B: Ugh
Down B: Ugh
Up B: Pretty good, I've killed with it a few times, but on For Glory FD maps, it seems super unsafe. Small improvement over Brawl up B
Overall, I hold the opinion that she's a bit better than the Brawl version, but not anywhere near Melee or PM levels. Still fun to play as though, and in the end, I'm less frustrated playing her in Smash4 than I was in Brawl.