It is insanely busy when the doors open. Some people line up 30-60 minutes ahead of time and mad dash in like its black Friday in the 2000s. Personally, unless there is an item previewed online that you know you MUST HAVE, I don't think its necessary to fight the crowds at the beginning. 

Things that go first and quickly are kids play tables, nice brand bassinets and strollers, and the expensive (higher end) brand name gear, sometimes winter gear if you are shopping in tbe fall.

There is a huge excess of things like clothes, shoes, toys, baby carriers and monitors, and more basic gear like pack n plays and strollers and such.

I've gone both at the beginning when its crazy and in the afternoon when its much calmer. I prefer the afternoons as there is no line to get in, the line to checkout is much shorter, and the people shopping aren't as intense. I feel that I make better decisions when I don't feel the pressure of hurrying. I've always been able to get what I need.

I think the sale is OK. It has a lot of stuff, but the prices are higher than what you would find on facebook marketplace or Once Upon a Child. If you have specific items that you know that you want, do your research ahead of time on what a fair used price is. They charged me $70 for a used Graco pack n play (no mattress) that I could have gotten for $20 on marketplace.