No, I haven't used Lindows 4.0; it only came out just recently. However, they haven't changed their policy about only being allowed to download updates for a year after the purchase as far as I know.
As to how it works using Windows programs, you choose which Windows version you wish to emulate - 3.1, 95 or 98. So when you install something that checks, it will appear to be the version you selected.
[ July 26, 2003: Message edited by: 3eyes ]