The biggest drawbacks I see to it on top of barrel life, or total lack there of, is that the brass is poor at best and has an even shorter life.
This is not a new caliber, Skip Talbot and #### Davis both took 505 Gibbs and necked it down to 338 about 10 years ago and found , yes with the 250 gr SMKs that were available velocity was about what the XT guys are claiming, but barrel life was none existant.
505 Gibbs is the parent case for 408 Cheytac, Kirby Allen and Richard Graves have been working with the same basic cartridge for a couple of years now and are finding the same issues.
Currently the brass is so poor of quality I have severe doubts about the accuracy claims that XT is extolling.
From personal experience, and there are several of us on this very forum who have and shoot them, 338LAI is a better option all the way around.
I just sold my own 338LAI to a friend, knowing it had 1500 rounds through the barrel and it still shoots 1/4moa
We know from Summerland that 2000 yards is easy with the 338LAI.
We know that a 300 gr SMK that leaves the muzzle at 3085 fps has over 6000 ftlbs of energy and we only need about 112 grains of powder to do all this, the XT uses 15% more and is using a lighter bullet, which physics tells us will loose speed and energy faster and will wind drift more.
Having seen quite a number of these rifles at the SHOT Show, as they seemed to be in almost everyones booth showing something, honestly I was wholly unimpressed with the overall quality and attention to detail for the money.
The sales guys seemed to allude to alot, but were unable to answer many questions that we already had answers to.
In short for less money I can sell you more rifle and you will be able to get components, reloading dies and vital info readily, no smoke and mirrors here.
And we are in Canada so if you have an issue, no paperwork and waiting years to get it back maybe.