Just realized the guy who trained me on layout in Spokane was right and my $400 laser was the problem
Six months ago in Spokane I was fighting a wall that kept coming out 5/8 inch out of square, and I kept blaming my tape and my helper. The old lead on that job, Ray, watched me for maybe ten minutes and then asked me one question: when did I last check my laser against a string line? I blew him off because it was a $400 unit and I figured it was fine. Turns out it had drifted 3/16 over 20 feet, which is exactly enough to wreck every plate and stud layout on a 60 foot wall. Check your lasers against a string line every few weeks, that's my whole point, and has anyone else had a self leveling unit drift on them without a single warning?