Yes, I really like vpn.ac as well. speed are consistently fast and every server works with US netflix, you dont really need to change to US server for US netflix, you can connect any of the server, say France and once you logged into netflix, it will show US content. Even inside netflix activity logs, it will show you are connecting from US Georgia.. I think that is a pretty neat feature I must say.
Mac's "Network Connection" tool has remained virtually unchanged in all Mac OS X versions. Thus, these directions should work when making basic VPN connections. However, it is best to keep your system upgraded to the latest version in order to address any security flaws and to be able to access more recent advanced options (such as using certificates) for configuring your VPN connection.