Super, or Mega? Both! SuperMega UL1
The Mountain Hardwear SuperMega UL 1 is a lightweight wonder of a shelter with very few drawbacks. It's light. Really light! 2 lbs. 3 oz. packed weight. That puts this fully free-standing tent squarely in bivy territory weight-wise, but you can actually sit up and change your clothes without resorting to inchworm gymnastics. It's designed for fast-and-light trips where packability and weight are the key considerations, and you'll be hard pressed to find another tent with the weight to features ratio of the SuperMegaUL 1.
Like any modern tent the setup is a breeze. Scout your spot, unfurl the tent body, and up she goes. The pole is one piece (five sections connected by two plastic hubs) so you won't be misplacing one if you get to camp late and are setting it up in the dark. No instruction necessary for which end goes where...little to little, big to big. If you were bored this tent could literally be set up with your eyes closed.
As you're pitching it for the first time you will probably notice some of the constructions details that make this such a compact package. The super lightweight fabrics are the most noticeable. People using tents made even just a few years ago will wonder if the tissue-paper like tent body and fly will stand up to a gust of wind, but they will, and then some. All panels on the fly are seam taped, as is the bathtub floor perimeter seam. The only water getting in will be in your Nalgene bottle!
Ok, so there were bound to be a few downsides. There aren't many, but one is pictured below: if you're much over 6 feet tall you might have some troubles with this tent. Our 6'4" model does NOT fit in this tent. Thankfully the majority of folks will fit into this tent, and part of the idea was to keep as small a footprint as possible to maximize the number of places it can be pitched.
Overall, this little number nails most everything on the checklist. As we were setting it up I kept jokingly calling it a free-standing bivy, but that's really not too far off from the truth. I know they have completely different use cases, but as a comparison the SuperMega UL1 weighs less than the OR Advance bivy, but you can sit up in it, change your clothes, store your pack under the vestibule...you know, tent stuff.
If you're frequently on solo trips (or refuse to share a tent) and want to shave a few ounces or even pounds off your current setup I'd give the Mountain Hardwear SuperMega UL1 a shot!