I surf with Opera (bye bye popups), design for IE and after finishing the design, open it with Netscape Composer and solve incompatibilities. 100% of public covered, no risk at all. Funny thing is that my own site
http://www.fdsign.com works fine only with IE, works barely decent with Opera and doesn't work with NS, but I needed that hahahahahaha!
Only use IE to check design (specially when modifying scrollbars) and when there's no other way (sites using hahahahahahas). Of course, for mail I use Netscape 4.79 Communicator Gold pack, way better than any crap (as somebody said: "look mom, no worms" and I'd add "no freezing", "ultimate control" "html mail construction in the fly" and so on)
And sorry Amp, but 100% is always more than 50, 80, 90 and even 99%, so when it comes to a business sense, I prefer 100%. Fuck, in a site getting 100k it means that maybe 10k won't be able to see the site
