I think this comment of the reviewer sums it up, for me anyway
"The program's biggest negative for me is the inability to use my Firefox add-ons. It's the same problem I have with Safari and Chrome: both are great browsers, but I'm not prepared to live without the productivity provided by my Firefox extensions."
And it doesn't really do anything that FireFox can't, having said that I will download it at some stage today and try it.