Nothing I'm saying here is new info, but I think it's reliable.
1. It varies from school to school, and program to program (that is, they aren't looking for as high of scores when applying to Master's programs as opposed to Doctoral programs).
2. Some have a hard cut-off, period. Yale and Duke are the main one's I've heard; Chicago and Baylor are similar there too, but not as rigid.
3. The majority, I think, do not need the Quant to be very high, but just respectable; I've heard over 600 at the lowest. I have a friend who applied to doctoral programs one go round with a V700 and Q4-something, and got in basically no where; the next round he pulled the Q up to 600 and got in to places he wanted.
4. That is to say, I haven't heard anything about a combo-score, although that's certainly nice to have. That doesn't mean it's not important at certain schools, I just have never heard it talked about in that way.
5. Other than the purely aesthetic quality of a number (710 looks so much nicer than 690 on paper!), I think percentiles are probably the most important thing at most schools. I told one program in particular my score, and their only question was, "What percentile is that? Oh, no problem".
Just what I've collected over the past year or so concerning the principality and power known as the GRE.