This is all personal opinion, of course. And I'm only a silver player, so my observations should be taken with a grain of salt XD
I think Roccat's style is too "reactive" and they're not as proficient at closing out games as seen with the Fnatic v Roccat game. Give it til Summer Split at best or next year and they will be monstrous. On the bright side, their style may very well be the key to beating teams like KTB or SKT. Their potential is exciting! :D
SK might give Roccat a run for their money if they stay on this current win streak, but I think Roccat is more cohesive.
SHC and Wolves are good, but they dont seem to have that monster playmaker. Millennium just seems outclassed, tbh, and Alliance...sigh. Amazing players but they're playing like it's Solo Q, not LCS. The lack of coordination, the lack of rotations. Such a shame.
As for NA, Dignitas is looking really good. CLG finally getting Dexter might actually be the final thing they need to reclaim old glory. Coast and XDG are simply too inconsistent and make major mistakes that nullifies any early game leads they get.
Curse is holding the middle firmly because of two issues: experience and champion pools. Voyboy appears to be comfortable on ~2 champions: Kat and Ziggs. The two things holding them above Coast and XDG at the moment is IWillDominate's smite steal prowess and Voyboy's shot-calling late game IF they are massively ahead. He knows how to close out a game very well.
All in all, it's shaping up to be a very exciting spring split