I use firefox on ubuntu as well and it works very nicely. Its RAM and CPU usage is negligible, sites load very fast, and the developer tools are awesome.
Some anecdotal data in the other direction, I made a comment about my experience on linux 5 months ago [1], and my opinion is still roughly the same (Except the blank tab problem has gone away after a Firefox update at some point, which WAS the biggest annoyance I had, so my mood has improved considerably since I made that post), and I have since taken to using Arch on an XPS, stock Ubuntu on another (more modestly specced) machine, and have had similar experiences there too.
That said I still use and prefer Firefox, but I also have to open up Chrome probably once every few weeks for various reasons, and it has occasional abhorrent behavior that I don't experience with any other program on the same machine.
I think something is wrong on your system.