Re: the difference between a 1P and 2P model.
For those extra two ounces you’d probably get better weather resistance, too.
Depending on the design, 2P models can often be more weather resistant than 1P models for only a small weight penalty.
This is especially true of most tunnel and dome designs. In the past, Hilleberg regularly recommended 2P models for solo use in challenging conditions but that may have changed with the introduction of a “Black Label” version of the Soulo (1P). I remember reading an account of a Red Label Soulo that was flattened by wind (!) above 10,000 feet while a 2P Jannu being used as a solo tent came out okay. Both structures use three poles but the Jannu’s larger size apparently creates a geometry that sheds wind better.
Roger’s tunnel might have been the exception. I remember that he made a 1P solo version for Ryan and I bet that it performs just as well as the 2P version that Roger has often written about.
For rectangular monopole mids. I’ll go out on a limb here and say that I think that a 2P version does better than a 1P version if the heights are basically the same, but if the heights are significantly different, the lower height of the 1P version trumps the 2P. Single pole mids reaching up into 4P+ territory need to switch to hexagonal or octagonal designs to get better wind resistance. An octagonal 1/2P mid is very stout but doesn’t have the best size/weight ratio.
Designers of dual pole trekking pole tents like Dan and Henry must have a good sense by now of the differences between the 1P and 2P versions of their various designs wrt weather resistance, so it would be interesting to hear from them about this — or from anybody else with experience in this area.
The X-Mid manifestly aims for the best user-friendly compromise among weight, space, livability, weather resistance, ease of use, and price, not to excel in one area at the expense of others.