There are multiple threads for arguments for and against. Even one that is Sticky on the beginners forum -
Should get you started.
I personally use and prefer glass, however there is always the chance that you will break one and bleed a lot....
with that said I have over eight glass carboys in heavy rotation and I have never broken or cracked one in the past five years. Not saying I never will, I am just careful and cognizant of the fact that you can get hurt.