The one that kills me is "In case you missed it". I read my twitter chronologically, and removing tweets from that order in order to show them closer to the top (and therefore later) is the exact opposite of what I want.
I've clicked that action every single time I've seen it for at least the past year and it still continues to show the very thing I want to see less often. It's absolutely infuriating.
Hmmph, well another data point is that I love the ICYMI feature and use it every day. My feed is too big to ever read every tweet and get to the bottom, so it works for me.
I am glad that it is useful for you. It bugs me though that Twitter is trying to force everyone to use their service the same way. I want to use Twitter more like an RSS reader to catch interesting news stories and blog posts. The fact that they are actively discouraging using their platform like this is infuriating.
Especially when one or more of the "in case you missed it" tweets has a like, reply, or retweet from me already. Clearly I didn't miss it. Why are you showing it to me?