I think your comparision is great. I have had an opportunity to use both shelters in the last year and think you accurately captured the spirit of these two shelters. The one place my experience is slightly different is when it comes to condensation resistance. I agree that if the weather is such that you can leave the vestibute open on the Europa but need to close it on Squall2, that the Europa is much better. But when the vestibule can be open on both I found condensation to be the same in practice, even though there is more mesh in the Europa.
I can certainly understand why the Europa is given a slight nod as the best general purpose shelter. I have found that the Squall2 is slightly better for me due to it's superior pitching. This works out in two ways. I often see more extreme conditions, especially high winds where the Squall2 is a better performer. Second, I am regularly loaning my Squall2 to people I am introducing to light-weight backpacking. The Squall2's easier setup helps win them over.