I have found the laser to be really helpful not just for the green distances, but also distance to a hazard and to clear it, especially on courses I've not played before.
It takes me 5 seconds to do this and I'm doing it usually while waiting for people to lay their shots, so hardly increasing the round time.
It's also amazing how many people without a device ask me for the yardage...!
Someone has just told me there's a Bushnell GPS app, which you download, enter the code found on your laser, and you have a GPS device on your phone, with hole flyover, all yardage to all hazards and the green, plus stat tracking options. Only trouble I can foresee is having to get the phone out of the bag each time! That will slow things down.
I dislike wearing a watch when playing, so that's out for me.