Having a good advisor I think is one of the most important things you can have in your graduate career. Some advisors like to really get their students out in as short of a time as possible and will support them as such. Others treat the students like graduate slaves (6,7,8,9 years). Most I think fall somewhere in between. Also, getting to know the people in your group is important. Some groups have a lot of drama, some don't.
I would love to post more details but since my username is my real name I won't. Wanted to use my usual SN but it has the name Pedro in it which the forum filter software detects as having Dr in the name.