I've slept over 100 (sometimes very rainy) nights in the Megamid (the heavier fabric version) with great success. When the 1-1/2 lb (tent canopy only) Megalight came out I snatched one up and have spent ~20 nights in it with similar, albeit lighter, results.
I tried out the GoLite Hex but found the hex shape to be much less efficient at packing bodies than the square footprint of the mids.
Megalight comes with 1 oz trekking pole connector so you can leave the tent pole at home.
0)A stick from the woods, ski pole, paddle or suspension from an overhanging tree branch will also erect the canopy.
0)One person and a fully assembled bicycle leaned against the pole will fit inside.
0)unlike my 2 vintage Megamids, the Megalight comes with a high vent which mitigates condensation. None the less, we affectionately refer to these devices as the "Sweat-a-Mid" and "Sweat-a-Lite". Staking through the 6" loops to raise the tent ~4" off the ground helps alot with condensation. I only only pin it close to the ground (on the windward side) in high winds.
0) With 1-2 people I use my 14oz GoLite Cave 1. For 3-4 the MegaLite is my go to tent. On the Tahoe Rim Trail with Aaron Sorenson and Michael Popov we packed 4 sweaty guys (two in the 6'4" range) inside. That's 6oz of tent carrying load per person.
0)For most camping I only see 3 reasons (all dubious) for a tent being double walled. 1)Better insulated - only a little bit warmer than a single walled tent and the same weight invested in sleeping bag insulation will net far greater warmth. 2)Bug protection - a headnet is vastly lighter and works fine for me. 3)Physical barrier to prohibit occupants from brushing innerside of outer canopy wet with condensate - using our brains to limit our body motions so as to not brush the walls is much lighter than dragging a fabric "fence" over mountain passes. The Mids are so large that it is usually easy to avoid the walls.
0)As much as I love this as a 3 season tent, it really comes into it's own when snow camping. Bury the lower edge to seal against spindrift blowing in. Don't worry about condensation. It will either run down the walls or freeze harmlessly on them. Dig the floor down 2' into the snow and you now have vertical walls which makes it fit 4 even more comfortably than in summer. You could add tie outs for heavy winds, but in stock form it will actually take some serious winds and still be functional.
0)Fast erecting. 4 stakes and 1 pole and you're good to go. Great for a surprise 3AM rainstorm while sleeping out under the stars.
0) Best of all: if you pile soil around the base of the pole for insulation and stack rocks from the campfire around the pole you can strip down, sprinkle water on the rocks and have a rockin' sweat lodge.