Most of the web pages that I currently develop make intensive use of the position layout features of Cascading Style Sheets, level 2. This specification has been published in may 1998 and could have been well accepted by all major browsers by now; the sad truth being that it isn't. Because of this the only browsers that display these pages perfectly are Mozilla and the mozilla-derived Netscape 6, as they are the only who are fully CSS2 compliant.
The lack of support in itself should not have to be a problem. The UNIX text mode browser Lynx does not support any level of style sheets. Yet it displays these pages reasonably well. This is because it displays the page just as the html flow dictates.
The real problem is that both Netscape 4 and Internet Explorer have broken style sheet implementations. As a result of this they don't display the page correct, as a compliant browser would, but they also fail to display the natural html flow.
Because of all this I must advice anyone to use either Mozilla or Netscape 6 to visit
my pages, as much as I may dislike `Optimized for ...' buttons on a website.
I have tested Opera 5 in Linux and it should do ok (although you may encounter minor issues in marginal situations).