Interesting question. I haven't used one, but have seen one in the flesh, and done a bit of research on behalf of a buyer. It strikes me that the scope does nearly everything for you! You obviously have to have all your variables programmed, so the algorithm can work out your bullet drop, and in this respect you still need to do all the work from an initial setup. Here it got interesting for me, because loading, chronoing, testing, confirming etc all lead to using a BDC turret with confidence, and on a "traditional" scope, dialling in elevation and windage corrections based on knowing the round's characteristics. A successful shot then depends on your ability to measure accurately the range, angle, wind speed and direction. You then need to use your ballistics app of choice to input the data, including humidity if you know it, elevation, air temp etc.
So the dS takes away a great deal of work, and of course faff. It ranges, and sets the aim point for you. Quickly, quietly and efficiently. But that's only half the story, and where I realised that it wasn't going to be the answer to all of my prayers, and there was in fact (from my personal perspective) a fly in the ointment.
That fly is windage. You cannot alter or dial in an accurate windage correction. The scope does try, inasmuch as you can set it for windspeed. In the App you have the option to set one of two windspeeds, ( I can't remember what they are, but) let's say 5mph and 10mph. Based on this setting, the reticle display then gives you brackets. The outermost mark is the aimpoint for a full-value windage correction at the speed you've set in the App. If however, the wind is not at 90 degrees, or isn't running at the same speed as you've set, you have to use "Kentucky windage" principles. Sure, the brackets give you a starter for ten, but the exact aimpoint for, say a quarter-value wind isn't there, so your success depends on your experience, not the gadgetry.
That for me means that the dS is not the correct scope for what I wanted to do with it. It is NOT a do-it-all solution for the sort of long range varminting I enjoy, precisely because of the windage limitations.
I then realised I was looking at this the wrong way round. I was trying to superimpose my personal experience and expectations onto an item that was designed for a different purpose. This is a hunting scope, designed to take away (some of) the guesswork and make things like a rangefinder redundant. At sensible ranges, with a round that is capable of bucking the wind, it would be ideal; a swift, reliable means of cutting out processes that only serve to delay the taking of an accurate and effective shot.
I therefore concluded that in the right hands, it's a great scope. Swarovski optical excellence (although some of the reviews appear to me to conclude that the overall performance in low light is not on a par with their clearest optics....) you simply need to spot your quarry, point your scope at it and pull the trigger. What's not to like? No need to carry a separate rangefinder, phone app or dope cards, just simple spotting binos and the scope does the rest.
There are of course a number counter-arguments, which I haven't articulated here, based on "who is this scope aimed at?", "who will the likely buyers be and will they get the most benefit from buying one?", but perhaps they should be saved for later.