My first laser level saved me three hours on a single shelf project. I used to fight with a bubble level and a tape measure forever. Now I can't imagine doing any kind of hanging job without one.
You said it saves you three hours and honestly that reminds me of when I first got my truck running after it died on me twice in one week. Took forever to figure out the wiring but once I did everything just clicked. Lasers and trucks are different things I know but the feeling of finally getting something right is the same. I bet that shelf is dead on level now too. Nice job on the upgrade man.