I am also very intrigued by the Desert Tech stuff, but from the rumours of pricing I've heard on them, (in the 8500$ range?- hope that's wrong), I think it's out of my price range for another gun that is in same calibers as the rifles already in my safe. Plus I have an order in on the new Ruger Precision Rifle for 1/5 the price, so will wait and see how it shoots before buying another big dollar gun.
I can tell you though that my Barrett is easy and quick to caliber swap between .308 and .338, and that at ranges between 600-1000 yards, there isn't really we much difference at all in poi between the calibers. In fact, I wouldn't say it's anymore then when I switch Ammo of the same caliber between different hand loads or switching to factory Ammo from hand loads. To me, as long as the impacts are still close and all you need to do is a little tweaking of the scope, that's all you could ever expect when I do a complete barrel switch.
Is it really all that important that it will still print the same tiny groups after you barrel switch, or you have to tweak poi a little? Not to me anyways. By far, my main concern is accuracy of each barrel and each caliber overall.
If it is also true that the cost for the Desert Tech stuff is 8500$ish for the gun and one caliber, (can anyone chime in on an actual quoted price for the Desert Tech?), then that is what my Barrett cost for the gun and all 3 calibers, (.308/.6.5 Creedmoor/.338). That spare cash you save on the Barrett certainly pays for a really nice high end scope, compared to the Desert Tech.
My Accuracy International AT, in .308, was about the same price as the Barrett initially, in that 5500$ range, but my 6.5 Creemoor barrel was even cheaper then the Barrett, around 1000$ imported thru Prophet River. Unfortunately the AI ATs can't be swapped between the short action-long action calibers, so no .338 for the AI, but for the cost of the Desert Tech, you could buy the AI, and another .338 and still be talking the same money.
Truly no wrong answer here though, and I would absolutely love to have a Desert Tech as well, but will be an investment that I will have to wait another year or two to swallow.