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Pro Cheaper and easier to use than Little Snitch
This app, like Little Snitch, selectively blocks outgoing connections, but it has a more detailed network monitor. Get this if you want an easier to use and more affordable firewall than Little Snitch.
Pro Normal system processes don't produce popups
It has internal filters for normal operating system process, so they don't produce popups, preventing the firewall from nagging you excessively. This feature can also be turned off.
Pro Tiny footprint
This app is tiny and fast. It won't annoy you with tons of popups, neither will slow your system down, not even on older Macs.
Con It is not well suited for security conscious professionals
The lack of expert configuration options leave us with only the most basic protection.
Con It defaults to allow all connections
Unless you specifically add an application to the blacklist, it will be allowed by default, making the firewall easier to use to the novice, but also letting you potentially leak valuable data by a rogue app.