Don't know about ProtoWall, but the problem with PeerGuardian lately isn't so much the app, but the size of the blocklist is so huge, any app, including Sygate will slow down. I use Blocklist Manager and download a lot of em, so I am blocking about 2.5 billion IPs, and when exporting the list to Sygate and not running the PG app, then Sygate eats up all my resources. The PG app has gotten much better about this, but if you already run a firewall, then you don't really need to run PG as well unless you want it's connection log, which is handy if you do get busted, you can go back and match the date/time to the IP and submit it to be blocked in future blocklist updates.