Is Seamonkey for linux better than Firefox?

I asked this question because of inability of buglessly playing videos using firefox. In order to solve this problem I have tried on my ubuntu box: opera, google chrome, konqueror, galeon, epiphany, and seamonkey web browser. And the last one is perfectly doing this task. So whenever I bump into the video firefox can't play I just grub seamonkey and it works great. It is easy to install just unpack and enjoy (http://www.seamonkey-project.org/). The only thing that keeps me from using it as my main browser that it does not have as rich set of addons as firefox does.