Classes: There seem to be a lot of lacking (sub) class options, I'd put that mostly on EA. Some of the standout things that need fixing is wizards being able to learn every spell, Rogues - just in general- no expertiese and the plethora of bonus actions everyone gets really take away a lot of what makes rogues special. And just a whole bunch of missing subclass features. Overall they seem very much still a work in progress and I expect that to improve a lot in the coming months.
Companions: This is my biggest concern. Mechanics can be fixed and polished. With voice acting, story writing etc. It's unlikely we will see big changes to the companions. And they're all very underwhelming. So far I can tolerate Wyll and Gale in my party, and Gale's only positive is that he isn't a negative like the others. I wish I could say something good here. But the companions just aren't doing it for me.
Alignment: Meh, it's not really a factor in 5e anymore, so nothing wrong with not making a big deal out of it.
Knowlege Base: Could definitely use some better UX