The setup pictured is a draw-through(or suck-through) MAF because the MAF comes before the turbo. When doing it this way, you must have the BPV recirculating into the intake after the MAF. (The setup shown is also doing this correctly). This is how most factory turbos do it.
You should not vent to atmosphere, or into the intake anywhere before the MAF, otherwise you will be venting out air that is already metered, and when you blow off, your engine will think there is more air then there really is and go very rich.
The other option is a blow through setup, where the MAF is after the turbo, on the pressurized side. In this case, you want the MAF after the BOV, because again, you don't want to blow off air that is already metered. Having a blow through setup give the ability to vent to atmosphere without any negative consequences.
Both setups work ok, it is up to personal preference. Blow through intuitively seems like it would have a more accurate reading to me, but I have no data to back that up. The disadvantages to blow through are that it may put more stress on your MAF since it's not designed to be pressurized and it is possible to get it gunked up with oil if you have any blow-by. Still many people do this type of setup without any problems.
