I think you can go either way on this one. The bypass valve will make sure your engine recieves the proper amount of oil.
More flow through the media is great, but it (seems to) come at the expense of trapping less junk.
Flip the coin and you have (potentially) more oil bypassing the filter completely, but the oil that does get filtered is cleaner (as much as it can be with a full flow).
Pick your poison. Given how many times you might pump a sump full of oil through a filter during a 30 mile drive, personally, I'll take the finer-filtering device.
Although in the real word I just slap on whatever I can get cheap. But back on topic, the general consensus is that K&N's flow the most.