I upgraded to high sierra a couple days ago and my MacBook has been freezing AT LEAST once a day. Good on you that you’ve avoided the upgrade, I wish I had too.
10.13 is terrible for people who use FileVault, in multiple ways:
1) If you upgraded to 10.13.0 your password is being leaked in the password hint.
2) APFS + FileVault performance is abysmal compared to APFS without Filevault or HFS + FileVault or HFS without FileVault.