crazy-max
Consolidate firewall rules into a single rule?
Don't know if there's any impact on system performance (probably not), but is there a reason for creating separate rules (more than 150) instead of merging them into one? I believe Windows Firewall supports this and ranges can be entered too:
64.4.23.0-64.4.23.255,65.52.100.0-65.52.100.255, 191.239.54.52,207.46.41.202,207.68.166.254 etc. Just a single, large line into "Remote address".
If anything, it will look better in the rules list. Perhaps the current method is preferred because separate rules are easier to enable/disable for testing purposes.
Multiple entries can be specified for remoteip by separating them with a comma according to the Netsh AdvFirewall Firewall Commands but like you said it's easier to separate rules for testing purposes. I don't know if network performances can be altered but this is not significant on a personal computer but can be on a router. We can try to benchmark to have an idea.
The improvement should be minimal, beyond human recognition, in the scale of milliseconds.
After some investigation there is no impact on system performance for firewall and hosts rules.
By the way, it seems that adding multiple rules (on the Windows Firewall) takes a lot longer. For example, I just added the new rules with WindowsSpyBlocker and it took around a minute. Adding a single (merged) rule would probably require a couple of seconds.