Please post some specific spell names when talking about changes. I've looked over some of the feedback and its not always easy to determine what spell you're talking about.
I looked at the Rift and I've played a Warlock for awhile so I'm familiar with the old one which was just big rocks. Honestly, I like the new one. It shows a glowing rift in the ground which is kinda cool. I understand this is opinion and not everyone will agree thought.
As far as the notes for bards, which spells? Some of the new effects still show the notes when you are casting but don't have the persistant note effects constantly playing. These were the types of things that had the biggest performance impact because if it was a group buff like Selo's, the notes were playing on everyone in your group and those effects definitely add up.
Please provide some more examples, we aren't beyond making some changes.