Yes, Gentoo is totally worth at least trying out. I have been using it since its inception, and it really is my favorite distro. Once you use it and get used to the customization, you will be hooked. It has the amount of customization that leaves other distros in the dust, and you will be wishing that you could just add a use flag or take away a use flag in that package.

Of course, that could be offset by the compile times, which if you don't have a fast processor, could suck. Also, if you have any hangups or bugs, the gentoo forums are some of the best out there so don't be afraid to search and ask.

Great advice from everyone in this thread. You will want to install from the Ubuntu install you already have too. That way, you will have a full desktop with internet while you install and you can use it normally while it works.