Once you have one in your Hands it make perfect sense to have everything built in to the Scope, I'm with Bruce on this. I was out the other evening with the DS35 not mounted to a Rifle just Hand held, I could clearly see Hares out past 400 yards, Then discovered you can Spot and flood the beam by pulling in and out, Something that I didn't see in Chris Parkins review,
and I have to disagree with that review saying the the onboard IR is only good for 150 metres, I could quite happily Id and shoot a Fox @ 250 - 300 yards with the onboard IR, If anything it's too powerful close in at say 40 yards, So if your a Ratter with a Air rifle maybe just a good old T20 LED based torch would be enough and give a clearer Image.
I have yet to test the Ballistic calculator, but I'm sure it will work fine, it's just a case of entering the correct data. I bought this to go on a FX Impact M3.25 FAC Air rifle and it will be perfect for that, in the meantime I will stick it on my 22.250 too see what it's like on a Rifle. I have looked through enough NV units to know it's Pretty good value for Money, even if it does look like the Star ship enterprise:)