I have been riding for 25 years. I have always used Campagnolo on the road and Shimano off road.
In an effort to move with the times, and since a change is as good as a rest I have twice made the mistake of trying SRAM off road (XO and XX) and once on the road (Red). I have always been disappointed. XTR feels like a robust product, whereas SRAM feels a bit flimsy and plastic. The finish is nothing to compare, and the feel is more reliable with XTR.
You pay extra for XTR over lower tier Shimano groups not only because it is lighter, but because it is harder wearing and longer lasting. With SRAM, it would appear that you just pay for the weight as the more you spend, the flimsier it seems to be.
So, for me, there is no question that XTR is the right choice. Just feels a more quality product and better engineered, finished and smoother in operation.