I'm going over some options in a Windows Tweaker and one of them is "enable NTLMv2".
I've looked this up a bit, but the main question I have: how can I benefit from this, and does it work if not enabled on other computers/servers?
NTLM/v2 has to do with user authentication over a network. The decision on the LMCompatibilityLevel needs to take into account the types of systems used in the environment and how high the threat of attack is. If your O/S is reasonably recent I wouldn't worry about it.
See NTLMv2 in wikipedia.org.