These Primaris Space Marines are huge. The posing is great and much more dynamic. It actually looks like there is a post-human inside that armour rather than a mannequin.
I have to admit, I like them. Even a whinging Nid player like me can appreciate that this is progress. In comparison, Termagants are the size of large dogs rather than small ponies. That feels about right to me. I don't have a marine army though and if I'd spent thousands of hours building and painting an Astartes force over the years, maybe I'd feel different. The look and feel is close enough that you can fit them into your regular army without it looking like a glaring inconsistency. Some SM players probably won't give a toss anyway. Just chess pieces on a board and this is another set to collect. As long as they are 3-colour, tournament ready and WYSIWYG they will be good to go.
Still not as tall as my kitbashed Necron warriors though. Those buggers tower over everyone! (I may be compensating for something)