I have read countless articles extolling the virtues of minimalist synthetic trail runners with mesh sides. Typically authors (e.g. Dave) take the viewpoint that there is no room for debate---WP/B leather shoes/boots are never a good idea. I'll admit I've tried to drink the kool-aid, and have a few pairs of shoes that fit the BPL ideal (inov-8, etc.) But I find they just don't work for me and my local trails.
In New Mexico our trails don't have any of whatever that wet stuff is in these pictures. Just bone dry dirt and cacti and pricklies in all forms. My inov-8's are horrible in such conditions! Dirt and sand comes through the mesh panels and over the low cut sides even with tight fitting gaiters. They provide no protection against the prickly local flora. And they provide little rigidity for scrambling up loose, dry, rocky mountains.
When I'm hiking off-trail anywhere below 10k ft in NM I bring either Keen Targhee II Mids, or Asolo Fugitive boots (and gaiters too). Both have a WP/B membrane which works wonderfully in at wicking sweat from my feet when the relative humidity is <10% and the only water in a 20 mile radius is inside my pack. They provide support for scrambly sidehilling and arroyo crossing, the thick leather keeps out cacti, and the high sides and WP/B membrane keeps the fine dust and sand outside my shoes and my feet safe from blisters. When there are no trails there is also no compacted soil, so I find stiffer boots are not as much of a problem, and in fact they seem to help.
Just thought I'd share my alternative viewpoint on all this. I am trying to lighten up my footwear, and have had some success in the alpine, but every time I'm out moving cross-country in the NM desert, my minimalist trail runners end up holding me back.