Asking about Audience Sync <Tips, Tricks and Use Cases>

Compared to any other platform that has audience sync how well does Braze compare, is there a type of impartial report? 

for those that use them what is the preferred way to use them: 

1) exclude ads to segements having done X event. 

2) create lookalike audiences ads for segments having done X event. in this case a normal ad. 

3) have a follow up ad for segments having done X event. example "can't wait to see you in this trip"

4) having an audience made for the segment that did not receive the original message (didn't open email or any other message) 

any other forms you can thing to use this? 

Thanks for your input.