Go back and look at the screenshots with the closeups of the Gnaars. It doesn't look like they redid the models overall, so the 'cone' shape of the teeth looks crappy. The body texture looks pretty 'plastic-ey' as well and that really drives down the immersion as well.
SS had a slightly drawn/cartoon feel to it's graphics, so slapping some uber high textures on them just doesn't look quite right. It falls into that uncanny valley that prevents you from really getting into the game.
It's kinda like comparing the original Doom versus a build engine game like witchhaven. The latter has higher details and more color, but the overall experience isn't there. You may not notice it right away depending on your graphic tolerance, but it will stand out in the overall game experience.
This comparison also works for other games as well. For example: The 7th Guest versus the sequel, the 11th Hour. Sometimes more is less.
And if I remember the news blurb right, the higher poly's did come at a penalty to the enemies on screen. Which if it means the game is Closer to SS2, than it is the first two FE/SE...it's going to suck.