My Solomid has the MLD bug skirt option and my short answer to your question is that I like it and would make the same choice again. I have been using it as my primary shelter for Montana and Wyoming mountain backpacking for a few years.
The longer answer is that it does not work as well as the netting on a conventional tent. I typically set up the Solomid at 5 or 6 pm, go about my business then return to the tent at 8:30 or 9 in the summer. I typically find 15 or 20 mosquitoes or flies in the tent, most of which are congregated near the apex. Most of them can be ushered out through the top vent with a few minutes of effort. The remainder take more time. Those that linger down lower are difficult to push out beneath the skirt; visualize the skirt not as hanging straight down but as forming an acute angle so that the edge comes back into the sleeping area. If you merely push the bugs to the bottom of the tent fabric then they are trapped in the v-shaped "crotch" of the fabric/skirt junction. I try to "cup" the offenders between my hand and the netting, pull my hand back toward the center of the sleeping area then push them back outside, a somewhat difficult process. It takes about 10 or 15 minutes of fiddling to remove the pests.
How do they enter the shelter in the first place? I have never watched the process but a few get in during shelter setup. I *think* most of them enter underneath the netting. The skirt never quite makes a perfect seal against the ground. Your ground cloth, equipment, and rocks can all be used to pull the netting down to the earth. On the other hand maybe I set up my shelter too high and partially create the problem?
Another option, which I added to my Golite Hex 3, is a DIY bug skirt. Buy the netting and a tube of silicone sealant, no sewing is involved. It takes about one hour of modest effort. The finished product does not have the nice snaps for closing the gap at the door but it works OK.
I have found the skirt to be a very good compromise for most conditions.
The photo is not very informative but it does give some idea of the location of the skirt remaining inside the footprint of the tent. In fact I can't see the skirt at all. I do see the beautiful tight pitch, though :)
