Personally, I understand why Sonic and Knuckles would wear bandages on around their arms. Muay Thai, Boxing, and plenty of other martial arts have some form of hand protection and bandages are one of the simpler ones, so that makes sense for Knuckles. As for Sonic, bandages could be used as makeshift gloves or hand protection for parkour except for the fact that Sonic already wears gloves. Now, here's the stupid thing: Why in the world are they wearing bandages around their shoes? What benefit is that? Without shoes and having bandaged bare-feet I can understand, but really? If it's some edgy design, then I have nothing to say...
Anyway, Tails looks more like a mechanic with him having a tool set and goggles; that's a good redesign or just additions to add to his character. Amy went from being a creepy, young, weird skirt-wearing pink hedgehog to looking like an older Amy who seems to be more capable in combat. I always had a strange vibe going around with Amy. It's probably her age and clingy-ness that bordered on yandere tendencies. Hopefully it's more comic-relief clingy "girlfriend" rather than that. So, an okay and large redesign. Knuckles, well, it makes sense since he fights with his fists most of the time. That said, it might not have been necessary, and all Knuckles got from the redesign was getting 'roided up. Seriously, he just gained muscle mass and bandages. Nothing else compared to Tails, Amy, and Sonic. On to Sonic, aside from the scarf which could symbolize his wanderer nature, he looks less edgy compared to the past Sonic, and more "friendly" like the chubby, original, kid Sonic.
Y'know, compared to Mario, Kirby, Street Fighter, Metal Gear, Sly Cooper, and Ratchet & Clank, Sonic getting a new design kind of throws off his "iconic" character. What do I mean by that? Well, look at Mario from his beginning to now and you'll see him being refined and given an iconic character. No matter what art style you add to him or different transformations, you'll recognize Mario. Same with Ryu, Ken, and Chun Li, who went from being sprites to extremely muscular fighters. There's this established character design. Likewise, Sly going from the PS2 era to the PS3 era did little to say: "Who's that?" It's Sly and it will always be Sly. Same with Ratchet who went from his debut design, to a more "realistic" or high quality design in Tools of Destruction, and became more fun, cartoon-y, and stylized in All 4 One. It's Ratchet and unmistakably Ratchet. For Sonic, he went from pudgy Sonic to edgier Sonic and nothing really was lost except for a slight change in character. The new Sonic just seems weird and that's probably what edgier Sonic was when he was unveiled. It's not drastic like DmC Dante & DMC Dante, or some of the Ultimate Marvel characters, but it's enough to create a sense of unease.