I have experience of both, having owned two 990’s and an F800GS. I have to say I really wanted to like the BMW more, but plain and simple fact is … the KTM has a bigger grin factor, is lighter on the wallet, except at fuel stops, is much more capable off road and is much more capable on a long tour.
My BMW had so many issues, head stock bearings, chain and sprokets life sucks, the motor needed new main bearings after on 22,000 miles, the on board computer information was unrelaible, the headlight sucks, all in all it was a real money pit. The bearings went just outside the two year warenty and BMW just stuck up a middle finger. In contrast KTM replaced the front wheel 4 moths out of warenty as the spokes were rusting.
The BMW is more suited to shopping trips than long tours, unless like Ewan, you have a support vehicle of spare.