Do you prefer a side-opening or end-opening tent? I’ve tried solo versions of both over the years, and come to prefer side opening. For one thing, I don’t have to sit-and-spin to get out of a side opening (nothing like a huge leg cramp as you fold yourself up to rotate when you need to answer nature’s call in the middle of the night.) For another, the vestibules seem larger (since they’re on the longer dimension of a solo tent) and it’s easier to stow gear out of the way.
I have noticed that end opening tents tend to weigh less.
I really only have side opening tents, but I've just about convinced myself I would prefer an end opening tent. Obviously what follows will be a theoretical argument and not practical. When I get an end opening tent I may come to agree with what appears to be the consensus opinion among lightweight backpackers that side opening is better.
My biggest gripe with tents currently is not being able to enter them from a standing position. I feel like I always have to do gymnastics once inside a tent getting dressed, getting into my sleeping bag, but ingress/egress is really impacted by door height. With an end opening tent (often) the maximum tent height corresponds with the door thus allowing a larger door opening. I will say I have a Tarptent Hogback 4 person tent. It is designed to be side opening, however we prefer to use it as an end opening tent (i.e. we setup the sleeping bags perpendicular to the door).
I prefer a side opening tent for ease of entry but I have an end opening tent. When I was experimenting with lightweight tents years ago, side opening tents were mostly single-wall silnylon and prone to condensation. I got tired of wet places on my sleeping bag. I finally bought a light, end entry, double wall tent and haven’t had condensation issues with it at all. My thinking then was, and still is, that I prefer to deal with more difficult entry and exit one to three times a day than to have damp or wet gear more often than I would like. My end-entry tent weighs about two pounds, keeps me dry and is not that difficult to enter. It serves me well but is not ideal. Looking at the cost of tents now, I’m willing to endure minor inconvenience rather than to spend a lot of money to deal with it.
I think side-opening is more convenient. As far as weight, the Zpacks tents are about as light as they come, and are side-opening. They have the added benefit of reducing the weight of your wallet to true ultralight levels.
Always remember that you are absolutely unique, just like everybody else. -Margaret Mead