Filatov has been very disapointing so far, but he's not at Cam Barkers level just yet. I have no idea what's happening with Barker, and while I agree he's in need of a change of scenery, I don't think Columbus touches him for that price.
Barker is a lot closer to bust status than Filatov is at this point.
Well, Barker has played, and will continue to play, in the NHL, and Filatov might be in the KHL next year.
Filatov already went back to the KHL. When he came back here after that season, he said that he had made a mistake going back and he now realized that, as he needs to get used to the North American game.
If Filatov goes back to the KHL again next year, I think he's basically given up on the NHL at that point. I wouldn't expect him to come back. Given that, I think Filatov sticks it out and earns his stripes for a couple of years yet before considering going back to Russia.
Personally, I'd take Filatov over Barker as I believe Filatov has a much higher upside. Although if he doesn't reach it, he'll be Zherdev v2.0.