Kronos
Used it at EY for 3 years. If you keep your requests simple and don't overcomplicate things, you will get excellent schedule. I did very well, especially on days off.
It uses an optimizer to try to get you what you want. It's a computer though, so it's following instructions which are your requests and the company parameters. Keep them simple.
AIMS is a manual system. Completely different. The operator build the rosters by hand.
Some months were better than others, but like I said, it can work really well if you keep your request simple.