I have enabled "Stealth Mode" in the OS X built-in firewall (which I left enabled and had that confirmed as the recommended route here). So Stealth Mode enabled and no ICMP blocks in LS3 and I pass the "All Ports" test (i.e. all "stealth" (green).
So whilst I do not know enough to make recommendations about your own system security, if passing the test is your concern, built-in OS X incoming firewall in Stealth Mode should help (at least it does for my system). But it might depend on what applications you have running which have open ports awaiting connect requests.
When I asked here, the responses were basically that LS3 is an application centric firewall whereas OS X built-in firewall is more system centric.
Stuart
So whilst I do not know enough to make recommendations about your own system security, if passing the test is your concern, built-in OS X incoming firewall in Stealth Mode should help (at least it does for my system). But it might depend on what applications you have running which have open ports awaiting connect requests.
When I asked here, the responses were basically that LS3 is an application centric firewall whereas OS X built-in firewall is more system centric.
Stuart