Air Flow question

I was reading about a system with positive airflow pressure and another with negative airflow pressure.  Sounds like you can create one or the other by changing the proportion of inward to outward facing fans.  From what I read it seems like negative airflow pressure tends to lead to better air circulation in the case but tends to increase dust build up.  Positive airflow pressure leads to less dust but you may have areas inside the case not getting good airflow exposure.

At any rate, would I be correct in thinking that if you went with h2o cooling then negative airflow pressure would work better because the cooling is happening inside the case and your primary objective is to exhaust out the hot air.

And then along the same logic if you went with air cooling then you would want as much fresh air entering the case as possible so you would want a positive airflow pressured case.

Lastly, are these generalizations not completely accurate and really these things have to be tweaked when stress testing is done?

Thanks Alex,

In college these guys I knew aimed their window fans so that they blew air out of the room and their room used to always be so cold. Made for ideal beer drinking conditions

for a full water cooled setup you should try having the radiator fans as intake, allowing cool air from outside the case to pass through the rads instead of hot air in the case being pulled out just my opinion, and something to think about