The newest version I tried was 7.2. It was awesome. At least it actually has some options. I definetely want to try this version. I will download it and see when I got some time. Netscape is cool.
The browser shouldn't have site compatibility, the site should have browser compatibility. If a website doesn't support all browsers, it isn't a website worth going to.
It will only use the IE function for sites that you specify that you trust. it won't let you use your old netscape or firefox saved passwords for the site. you will have to manually type it in, the first time you use it with the IE engine for security reasons