In the late 90s I was trading stocks using Scottrade and had an issue. Called Scottrade tech support and they asked which browser I was using. IE I replied. There was a groan followed by a request that I switch to Netscape due to all the technical issues with IE.
I can't say I really remember but I don't recall Netscape having any more problems with web sites than IE after I switched.
As far as "winning the browser wars", nowadays browser choice is a personal one and no different than what clothes you wear or what car you drive. Technically all of them are pretty good so which one you use should be based on its interface and if it suits you ... except ... IE.
Inept at best, IE is the worst browser on the planet, technically speaking. It's the only browser you know you will have to write hacks for. It's the only browser you know won't look or work the same as the others, speaking as a developer.