I've only ever seen the Squall 2 in use once, and I wasn't impressed. Four of us were camped near Blackbeck Tarn, above Ennerdale in a couple of venerable TN Trisars. Not sure why we had such heavy tents with us, cos the forecast was good and the wind pretty light, by Lake District standards.
Anyhow, a bloke pitched his Squall 2 near us and I went over to have a word with him about it. He sang its praises, but I later noticed, after the wind had risen just a bit, that he seemed to be spending a lot of time trying to keep its doors shut and generally stop it blowing away. It might just be that he didn't know how to use it properly, but my impression was that it wasn't up to the job in conditions that were by no means extreme.
I've since used other tarps and pyramids, and they all seemed a lot more secure and practical to me than the Squall 2.
Never seen the Rigel X2 in use, but I'd think it would be very tricky not to touch the sides with two people inside.