I have a Bushnell 1500 laser and a GPS watch and I prefer the ease of the watch. Just glance at my wrist and get Front, Center and Back yardages. Every so often I get fooled with the wrong color flag, but I'm generally playing for the center and not so good that I need an exact yardage. It's gotten so I feel naked without it.
I do like to use the laser to "map" a course if possible. I joined a nearby club this year which is pretty tight and in some casual rounds I've lasered yardages to doglegs, trees, hazards, etc. My watch is a cheap one and doesn't always have that data and no ability to log it manually. My laser has slope and I also used it on 3 steeply downhill par 3's to learn the yardage drop. It's definitely a handy device, but I don't like playing a regular round of golf with it.