Now perhaps a bunch of these are preference/design choices, but whatever, especially the combination makes it suck imo:

- looking at a reply via notification or reply tab does not show what is being replied to;

- selecting a reply makes you go to the top of a thread making you scroll down to go to the actual reply, instead of showing you the reply directly;

- it only loads specific subthreads, not the entire thing with all the replies etc.

- this forces you to select a comment to see its replies;

- that again brings you to the top of the thread first, not the reply, you have to scroll down;

- it does not tell you if a post has any replies, let alone how many.

- scroll speed

This turns everything into a giant guessing game. Does it have replies? Lets find out, lets scroll down at a snails pase; ok cool this thing has comments. Does it have any other subthreads? Well who the fuck knows, only way to find that out is to brute force your way through i guess, reloading the thread over and over and over and over again turning it more into a blind maze you have to rewalk everytime than anything else really.

- it does not load data by itself, for instance if someone is referenced it will just throw out a ???, and only after selecting the ??? and it loading the profile will it know who/what it was and remember it.

Thats on top of my head.

Also, posts sometimes dont fit the screen and will just cut of the part on the right (even with the side tab tucked in), and will only fit the screen after selecting the post specifically.