I can directly compare United and Swiss, and United is still a lot more slow to fill the same plane.
Not to mention Boarding Group 1 means nothing. Army veterans, children, people with disabilities, GS, and 1K board first. And the line of that entire group in my experience is comparable with the line in Group 1, which is usually fairly large.
This has yet to cause my luggage bin bag to be misaligned with my seat, but it's irritating to be given Group 1 and not board first. I'd rather be given Group 2. And have that group above be Group 1. And I wish the categories of passengers qualifying for Groups 1 and 2 were a bit more narrowly defined (or the statuses hard to get). The lines for both and then Group 0 are, in the aggregate, always huge.