Biochem grad student here... I only had one final, since I was only taking one class that lasted the full semester. I did have some other paperwork to do before the end of the semester (like getting my committee finalized) and that's all done now, too. Yay!
I'm not really taking much of a break, I'll be in the lab pretty much every day other than Christmas day and New Year's day... but it's nice to have a few weeks off from the classes, journal clubs, lab meetings, seminars, etc.
I'm already dreading next semester, though... I'm TAing a lab course, plus taking a 3- or 4-credit class and two 1-credit classes. In April I've got my yearly student seminar and a journal club to present in the same week. And all of this while starting to write my proposal and prepare for my qualifying exam, which is this summer. Eww.