My granddaughter, in her 20's, is hoping to thru hike the AT in 2017. After a 3 day trip with her mom and me in NY, she likes the idea of going UL. She has a great sleeping bag and pad, and I want to buy her the tent. I'd like to hear your thoughts on a tent, 1 person or 2 (she will hopefully find a partner but should have her own tent, IMO). What is sacrificed insofar as comfort is concerned with a UL tent vs. a very lightweight tent? I'll probably want to buy it at REI so I can apply my dividend, but could buy from another source if there is a great product out there. Thanks for any and all suggestions.