I have recently started playing more at ACR. In the few days that I have stuck my nose in, I have noticed that there is much more traffic in the evening and later at night. Whenever I check the tables in the morning, there are a handful of 6-max tables going and only one or two full-ring tables. At night, there are many more of both. So, in terms of table selection and traffic, evenings and nights are busier. I have no idea if the tables are "softer" at any point, but I would imagine that more players means more variety in the type of players. If you are looking to multi-table full ring, then night would be best. 6-max seems to be busy enough to multi-table at all times that I have checked.
I just realized that you didn't specify what stakes or games that you play. My experience is based on NL2 cash games.
EDIT: Never mind. You did say micros.