I don't think the Sentinals look that great like that...they sort of look like a big metal railing pattern. And as for Angel, I think he looks good, but I'm not too fond of the design for the metal wings
They don't have to be superhuge. But I would like them to be bigger than average. Actually, bigger than Collosus... I just want to see the characters looking "up" at this thing who's only objective is to destroy them and everyone like them. It would seem like an insurmountable struggle, making it even more important that they defeat them. Also, if the sentinels are a bit smaller than they were in the cartoons, then they could shove more of them in there.