Ok, i can address the complains about the render, but one thing is certain: the model is fantastic and very well done.
I know by experience how hard and how demanding is to do a 3d model, bone it, textures, prepare the scene (lights, camera, effects, etc), not to mention all the rendering time those guys spend on each image and try, plus an ANIMATION (Takes alot of hours or even a whole day for render a scene of a few seconds, depending of the power of the pc that's being used and how many effects (reflections, etc) are played on the scene.
the one issue comes with the textures, the most visible part of the model. After checking critically the Render, i can mention 4:
1. Yeah, the anime hair, which is really difficult to make in 3d. The problem was that the hair locks don't blend together, maybe because of their transparency or shading. Other characters like shulk, roy or even Ike and Ryu has some twisted hair, but at least each hair lock blend together so well that looks as a whole, instead of separate parts. And about that, the hair doesn't look connected to the head, it lacks texture of the hair on the head, lack of shading on the head produced by the hair, which in turn make it look like a wig instead.
2. the eyes, i agreed completly that produces an Uncanny Valley effect, because they tried to mix Pit and Roy eyes, which is what they went wrong. All the realistic, anime-like characters cas their eyes made around their original source material, Link doesn't have the same eyes as roy or as pit, are completly different styles, and isaac should been keep true to that (Golden Sun eye style, or for a more recent base, Dark Dawn eye style=
3. The leather, after comparing it with other character like Robin (best example of boots, resembles isaac's), link, ike, pit and others, i agreed they just overdid the texture, specially on the boots. A more slight approach on that would been better i think.
4. (The thing nobody noticed) The ear wasn't modeled, is true that in smash 4 artworks the ears looks clean, but al least you can see the detail, here it just...loks plain (i am complaining about an ear, wow)
And that's all i got. Don't take it as a rant, i still love the work and the effort done on them, but i hope this could understand how some people didn't liked it (exagerated or not)