Before this latest Gmail UI refresh, you could do this: from the message list, hover over the sender of a message, and then from that popup dialog click on the sender (iirc) and you would get all of the emails from that sender. I used to use this all the time to quickly manage my inbox. I wanted to scan these emails but usually didn't need to read each one.
That's gone in the latest refresh. The best I can find for it is to select a message (via checkbox) and then use the message list header dropdown menu to "Filter messages like this", which then brings up the filter dialog and the list of filtered messages. 4 clicks for what used to be a hover and 1 click.
I know, seems trivial, but it's completely disrupted my email workflow... anybody know if there's something I'm missing and this functionality is still there somehow?