Had one. Sold it as I didn't think it was worth the premium. Also, it got close for a first-round guesstimate, but I get much more accurate solutions using a Bluetooth Kestrel and an Android phone. An interesting toy, and kudos to Barrett for giving it a try, but it ended up not being my glass of bourbon.
If you're going for the "wow" factor or the tacticool look as some call it, go with the BORS. If you're going for practicality just get yourself a simple ballistic calculator or one of the shooter apps for your phone. Not only do they work just as well if not better but you'll save yourself a ton of money.
I,m sorry I do not agree with the above statements I have been using on for two years and I really have learned to see it as a fast and effective tool for the rifle you are using it on. Now there is a learning curve to it and you have to spend time with it. Why others do like the hand held ballistic computers and the I phone apps is they are easy and you can have 100 different rifles in them that is true no question. But the BORS on top of the M82A1 is a package of sorts once setup it is there, to work with you and the gun as one unit. Is it a absolute need? NO. Good fundamentals will never be replaced by fancy stuff we screw to the tops of our gear but it is a helpful tool to me making faster shots. The other thing is if you are on a limited budget this item is probably not for you, as you can only use it with one weapon. The one problem I have ran into with the Iphone app is do you know how embarrassing it is to at a shoot and forget to turn off incoming calls and be ranging a shot a get a call from your mom