Meh, most of this match seems to have been covered in detail already. My biggest problem with this matchup is predicting which aerial will be used when I move in to attack (If Fair, I can shield and grab before you can get another move out, whereas if it's a Nair, well, I don't want to get so close.), or for that matter, what will be used period.
A single mistake on Kirby's part can lead to a whole lot of pain. Yeah, we have to work to get inside the sword, but we also have to make sure we can stay inside (jabs, Nairs, throws, and occasionally even Utilts can make this difficult.).
On the plus side, comboing Ike isn't all that complicated, and Kirby destroys Ike offstage. Aether's really not all that hard to counter as long as you know when the SA wears off. Stone effectively counters it, and aerial hammer and Inhale (I think... I might be wrong about the inhale.) can both work too, though the spacing/timing can be hard to get down. Otherwise, jump behind the sword if you can and just Bair him. However, if you don't know for sure that you can intercept Aether, don't try it: Kirbycides are painful, and even if it doesn't kill you, who wants to get hit anyway?
I would always spit Ike, since you can really screw with him with inhale. Shoot him under the stage and he's screwed. Jump offstage with him and shoot him, and he's usually screwed as well, especially since he'll be busy mashing buttons to avoid a Kirbycide. Realistically speaking though, inhale's not a move you'll use much in this matchup.
...I know I had more to say, but my mind kind of blanked out, so maybe I'll return later.
I'd say this match is in Kirby's favor, but not too much. 60-40 at the very most, and more likely 55-45.
Edit: Oh, and for CP stages, I've found Lylat works well against Ike, as does Japes, Frigate, and to a certain extent, BF and Norfair.