missing information during battles
There are a few categories of important information missing during battles in Live.
When an opponent plays a card that takes cards from the discard pile they're flashed on the screen unreadably fast, if at all. While it's maybe possible to work out what they took, that shouldn't be necessary, and it's not in the physical card game. Similarly, a few times the card art for cards selected from the deck hasn't loaded so I wasn't able to see what the opponent took (this was in cases where they were selecting a specific card and needed to reveal it).
Also, with attacks like Apex Dragon on Regidrago it's hard to know what attack was copied. There should be a way of seeing the attack name, so you could know if it placed any additional effects.
Both of those problems are worse because, as far as I can tell, there's no way to look at anything like a game log. In PTCGO if you missed something you could check the log and see everything that happened, just like when you're playing in paper you can ask your opponent what they just did.