I haven't checked a lot of the new effects out, but a few stood out to me as less functional (even if more pretty) than the original. The two worse in this regard are Quagmire and Firewall. New Quag looks beautiful, but it has some major issues: 1, the animation stops before the effect does. It is true that it restarts, loops till it needs to, but for a small period of time the effect is simply not visible at all. The exact same problem is present in firewall as well. 2, the effect is less messy since there's only one stack of bubbles, but these bubbles kinda go up and only up and by the end of the animation the entire effect is roughly one cell off from the actual position of the skill. Firewall also has the disappearing problem, but when the effect is actually there it's not transparent at all. This way it can fully cover the mob(s). See
here. The coverup issue is also a problem within firewall's individual cells. In ceration camea angles you might have a broken wall, eg the middle section is missing, but you can't see it because another part is covering it up. Some status effects by mobs are also harder to spot, like poison and stone curse. It's worth mentioning that some effects are actually better in this sense, eg LoV animation actually covering the area of the skill is glorious.
As for the looks of the effects... It's a mixed bag really. New SG looks great, New thunderstorm and lightning bolt are awesome. Meteor Storm, Bragi and Idun look terrible. Mammonite feels less weighty and not seeing the coinpurse is just sad. New LoV is... I donno less exciting than the old one, but since it covers up it's area well, it's fine. The changes in priest skills felt kinda unnecessary to me, but those are neither really better or worse. Oh... And new Quag is pretty, it's just rather difficult to comprehend compared to the old one, but I've already written about that.
A lot of the changes are fine I just probably need to get used to them. For example, I am not even sure what changed in occult impact's effect, but something if different. Not bad just feels odd until I get used to it. I think that's all, but I'll write my opinion down on the remaining changes if/when I see them.