PRS Talk Lazer Range Finder w Ballistic Calculator

Yup most matches now just give you the range anyways but checking with your own laser isn't a bad thing. There will be stages you can't use it but it's always good to have a laser.
 
I would recommend a separate ballistic solver as well. If they give you all the ranges for the match, it's a pain in the ass to have to re-range everything just to get your ballistics. My friend is selling his AB to get a Kestrel 5700 just for this reason.
 
Going to use it for the ballistic calculator built in.

Some of the longer stages/smaller or obscured targets you may not be able to obtain a laser range, and subsequently no solution.

Additionally, some stages (ie. elevated platform that can only facilitate one shooter/RO at a time) you'll end up slowing down the match flow.

It is a nice system when it works, to leave the smart phone in the pack, make a wind reading, thumb the wind into the SK2400AB, range target(s), solution, shoot.

If you have a backup plan, i.e. data cards, that your proficient with, I believe is the basic key that most skip over in search of a tech solution.