I'm not too fond of the fact that Olimar can only have 3 Pikmin now and they're plucked in a set order. Getting the Pikmin in a random order was what made playing as him fun.
THIS. I thought I was alone. I HATE that the 3DS version exists. It's completely unnecessary. I remember when I said a few months ago "The 3DS version is going to drag the Wii U version down. Mark my words" and everyone was like "Of course not, Sakurai knows what he's doing".
I think the idea of a Portable Smash Bros. alone makes it quite appealing to alot of fans of the series. Not to mention more people still have more 3DS's then Wii U's. At least initially, The 3DS version will outsell, and make more money then the Wii U version will.
I remember when I said a few months ago "The 3DS version is going to drag the Wii U version down. Mark my words" and everyone was like "Of course not, Sakurai knows what he's doing".
The only thing I found all that bad about the 3DS' limitations was the Ice Climbers having to be removed. Otherwise, the game will still run as smoothly as any other game in the series. And still has it's own unique flavor to it. And what other changes has actually been changes for the better. (Zelda & Shiek as well as Samus & ZSS being separate characters, Charizard being alone without the fatigue gimmick, and Olimar being buffed as a balance of having less Pikmin)
And we know nothing of what the Wii U version has other what it shares with the 3DS version as well as the different stages. The only thing that we know the 3DS version dragged down the Wii U version was a few characters in the roster and some of the more complex characters had to be scaled down to something simpler. Those are things that will easy to get used to in time. We still have the biggest and most varied roster of the series. And it's two versions of Smash Bros. to play and enjoy that will have different things going for them. It's kinda crazy (But really cool) how we're not just getting one Smash Bros. game, but two of them by the end of this year.
At the end of the day, the 3DS version does feel like a scaled-down SSBU. The lack of modes absolutely proves this. At least the Wii U version probably has Special Brawl and Stage Builder.
I think of the versions of Smash 4 as one of the few games that can kinda be both two games but also one game at the same time. It can be two games because there will be exclusive features in both, as well as stages and bonus content like trophies that won't be in the other version. (We just don't know what will be unique in the Wii U version yet, hoping we'll learn more in the October Nintendo Direct whenever that is). But it's also one game because of the same roster and general gameplay. And it's further made more interesting in how both games can connect with eachother.
So I kinda feel it's like this: If you only have either a 3DS or a Wii U and you can't afford the other system. You still have one complete Smash game regardless of your system. But if you do have both, you have one truly complete game.
Both are the same core game that you get to experience in two different ways with enough differences to make each feel unique without making someone feel like they are missing out by not having both.