They're fine, but the models that have internal splines for removal are a pain to remove as the tool won't fit over the lock nuts (doesn't matter if your hubs are Formula, Phil, etc). So you have have to remove the locknut or endcap (Phil, and pray the drive side breaks free first ) to remove the freewheel.

Their double-ended freewheel tool is awesome though, it works on pretty much every common single speed FW out there (ACS, WI, Shimano) and you don't need a vice to use it.