John, I think there are still a couple factors that make solo+ shelters attractive:
– Single trekking pole. Some fast-packing hikers like using single trekking poles. I use two poles but need a single pole tent because I need a pole to be free so I can still use it to hike around after setting up camp. 2 pole tents take away my extra trekking pole. That’s also 14+ ounces dropped by losing a trekking pole for single pole solo hikers.
– There is extra weight to be saved by removing features, like zippered doors. Altaplex comes in at around 5 ounces less than an X-mid Pro 2. 5 ounces is quite a lot in the UL world when my base weight is already just a hair over 9.5lbs in summer. I’m not trying to promote the Altaplex or anything, as it is still a sort of quirky and floppy design, but I think it’s a great base to start discussing tents cut just large enough for larger folks. I also think having the single, taller pole in this tent helps make it much easier to get in and out for big guys. Crawling up into a ball to roll into the tent isn’t fun after hiking 15+ miles with heavy elevation gains and being all sore. With an Altaplex pitched high, I can practically walk into my tent hunched over.

