The nearest I have ever used to a mid was the Six Moon Designs Lunar Solo, which is a 6-sided sort of half-pyramid. It did very well in Rocky Mountain thunderstorms (my first six days out, it drizzled all day until about 4 pm when a whole series of back-to-back thunderstorms with hail and high wind gusts. seemingly from all directions at once, kept coming through until about 9 pm. It did seem a little more wind resistant than other tents I've used. I sold it because it was too small (not enough room for me and my 75-lb. dog. It was fine for just sleeping, but not when the dog and I were cooped up for several hours on end. I also found that the Lunar Solo had considerably more condensation than other tents I've used, such as the Tarptent Squall II or the Squall Classic once made by Gossamer Gear. I sold the Lunar Solo to phat of this forum in 2010. The last I heard, he's still using it when above timberline in the Canadian Rockies (when in the timber, he hammocks), and he's still finding a few stray golden Labrador hairs inside.

While I've looked at mids in the past, all the ones I've seen required a separate bug tent or ground sheet inside, which made the result heavier than a standard cottage manufacturer tent. I know that on some of his expeditions, such as his Alaska-Yukon expedition, Andrew Skurka successfully used mids from Mountain Laurel Designs. (Now that he's working for Sierra Designs, he probably won't comment on the MLD mids, but you can find accounts and gear lists of that AK-Yukon trip.)

In the end, only you can decide what tent suits you. Before actually sewing or buying one, I suggest you play around with a large tarp or some plastic to make a model tent of the design(s) you envisage. After my experience with the Lunar Solo, I srongly recommend a vent up at the peak, as well as around the bottom. Remember that if it rains on a regular mid, you'll have to close the door, or it will rain into about 1/4 of the tent. Closed-up tents get awfully soggy inside from condensation!

You might want to look at the tents made by Tarptent.com for other ideas.