There is a poll and discussion about Open OS vs Lineage OS:
If you’re specifically asking about FP OS (not Open), then this is a new discussion.
It might soon be based on Android 8.
Apart from the standard Android changes Lineage OS has some neat features that you might know from Gravity Box and other XPosed modules if you ever used that (e.g. Privacy Control & ability to modify buttons behavior and toggles).
Absolutely.