I think it is ok but the header takes up more space on mine than the way I used to modify mine on IE6. I am not used to tabs. I tried Firefox a long time ago but it didnt get along with some of the websites I had to go to so I got rid of it.
I downloaded it and used it for a while. It wouldn't load a number of websites that I tried and was generally very slow. I don't like it but I am sure when it is done with Beta testing it will be good