For what it's worth, as one speaking as a current PhD student in what I think to be a good and competitive program, the GRE is important, but not in the ways people tend to think.
1. Combined scores are ONLY important for scholarships and awards. This can matter tremendously. The difference between a 1300 and a 1500 can be going from a basic stipend to a presidential scholarship, adding upwards of $5,000 to $7,000 on top of your award (assuming the program is fully funded).
2. Quantitative scores mean nothing to a committee EXCEPT in comparison to others. If you get an 800 on the V and a 400 on the Q, you are competing against another student who got an 800 V and an 600 Q - NOT a student who got a 400 V and an 800 Q. This might go without saying, but it is important to remember. Don't let anyone fool you into thinking that the Q matters ON ITS OWN. It is a part of the big picture, so when comparing a group of students who have, more or less, the exact same application - the Q can be a factor that helps one over the other. But experience, master's degrees, previous schools, work experience, relationships with profesors...all of these matter more.
3. Quantitative writing is more important than you might think - again, for the purpose of comparison. Otherwise, on its own it doesn't matter that much.
Hope this helps.