What do you dislike in ATB Systems?

I want to know what are disliked in specific atb systems or the atb system concept in general. Just feel free to share that 
For instance, I dislike atb systems with:
Fixed atb wait condition - Sometimes I might want to be more relaxed, so I might want the atb wait condition to be true whenever a party member can act(the loosest atb wait condition); Sometimes I might want more challenges, so I might want the atb wait condition to be true only when an action's executing or a message's displaying(the strictest atb wait condition). Therefore as a player, I want to be able to change the atb wait condition on the fly.
Hidden actor atb bars - To me, it's like hiding the actor hp, mp and/or tp bars. As atb bars display their actors' atb values, which is one of the most important information in atb system battles, I want to be able to keep track of them easily. At least, if the actor atb bars are hidden by default, I want to be able to change that to be shown instead.

I agree with both of your thoughts. I don't really have anything else to add though, sorry.

1 more point to add:
Slow atb refill speed(from empty to full) - While almost or just instant atb refill speed results in ctb, I don't want to play with atb systems having average atb refill speed as more than 10 seconds(in the past I've briefly measured my tolerance on this and it's roughly 6 seconds at most). As a player, I feel that it's just wasting my time lol