There are just so many unknowns. Seems to me that getting old software and drivers to cooperate is already tricky enough as it is without having to worry about something that might be mysteriously changed or missing in WinFLP. And there's the whole questionable-legality.
I've been using FLP on two of my notebook computers for a long time now, and the only issue I've run into is that .NET won't update past a certain point (4.0 or thereabouts). I never use the features that were removed from the OS, so YMMV.
I still use XP on my desktop, but FLP saves a lot of space on these smaller HDDs. Is it faster than XP? I'm not sure.
All of these computers run Firefox just fine, so I don't know why they would need to be kept offline.
What really kills it for me is no Compatibiity tab for executable files.
Maybe it's just me, but I've never gotten that feature to actually do anything. Is there a list somewhere of games/programs that require it?
Either the games worked without running them in a different compatibility mode, or I had to run them in DOXBox, or on a Win9x machine, or in Virtual PC, etc.