Here's a list:
- broken threads (I tap the reply, the rest of the thread is missing)
- "nostr:" urls are broken all over the place.
- for some reason images don't always load (is this NIP-95 crap still?)
- reposts/quotes should rebroadcast (did ya'll already get that one? I forget.)
- mute words
- custom feeds (can add defaults for newbs, like #photography, #art, etc.)

These are a few things I have to explain to new people, which seem like a degraded experience to a noob coming from Twitter, et al. or seem to be essential to manage the differences. They aren't a reflection of my feelings, to be clear. Just what confuses my fam and friends. 

 Broken threads is a big one too. Being able to open and close a thread within a thread and continue reading replies.