While the carts with GPS systems feature is indeed nice, I've found over the years (even with the newer models at the resorts down in Florida, MB, etc.) to have at least one or two holes per round where the yardage to the hole is off by 10+ yards. I could maybe understand a couple yards margin for error, but 10+ yards is pretty significant.
Hard for me to trust them when I have a laser that I know is reliable.
The only place where I'd bring it to the tee box, lay it down, forget that I brought it to the tee with me and left it there, and then 15 minutes later realize that I don't have it... then go back and pray that the guys playing behind me are honest people who would return it back to me - much more opportunistic to happen on a par3 imo.
Had this happen several years ago, playing a local place where the last hole is a par3 - forgot about my laser I laid on the tee box, didn't think anything of it until I was getting my stuff out of the cart and putting it in the back of my SUV.
Immediately went back to the tee 20 minutes later, didn't see it. Two guys playing behind us were putting their bags in the trunk of the car and I drove up alongside them and asked if they'd found it.
"Uh, no. No, we didn't see anything."
I could sense that the guy was lying through his teeth. But nothing I could do about it. Paid $299 for it and that was back about 10 years ago. These things are easily $100-$200 more today.
That's why I don't take them to tee boxes on par3's that are off the beaten cart path. Really don't have that problem at my club where I play most of my golf these days.