Tundra,
I rode the KTM 990 Adventure, and Truimph Tiger 800 X/C before discovering the Tenere. The Tenere is sure nice, but if you want power and speed, I think the new KTM or the Mulitstrada will float your boat over the Tenere. While I'm no racer, I reason you'll find Tenere too heavy for serious fun at speed (at least I do). It's sheer bulk and power-to-weight is simply unfavorable for really quick handling. (Then again, I came from a 360lb Ducati Monster prior to the Tenere). I do find the Tenere a terrific bike for long journeys in any weather, carrying everything but the kitchen sink. It's a spirited pack mule in my book. Fast enough, but not really quick. I've never taken it on a serious dirt ride, but it's fine on forest service roads with stock 90/10 tires, as long as I'm conservative in my riding style.
I'm sure you've noticed that on paper, the new KTM, BMW and Ducati are much more powerful than the Tenere. More importantly, the KTM -and especially the Ducati- are also substantially lighter. Their power-to-weight ratios enhance everything and would be paramount to my decision... so long as cost were no object. With the Yamaha, I'd worry I couldn't pick the damn thing up if I ever tipped over! (With the Duc, I'm sure I'd find myself riding conservatively off-road for fear of a putting a scratch in it… but the KTM seems ready to take it's lumps and add to it's character.)
However... if you're looking for bang for the buck, the Yamaha wins, hands down. Especially if you score one on deep discount like I did! And you'll have plenty of scratch left over to accessorize it (and add more weight, ha ha.).
While I am not mechanic, but I never had any problems with my Ducati over 3-years and 15,000 miles of spirited riding. I found the KTM's to exude quality too, even more than the Yamaha I dare say? The Ducati's valve intervals are much longer than before and a non-factor in my book, as I prize riding dynamics well before maintenance needs. Then there is the new tech of instantly adjustable suspension on both the new KTM and Ducati. Complications of the added electronics aside, the ability to tune the suspension (as well as power delivery) on-the-fly is very appealing. With all the added speed those powerful and expensive bikes bring, I'd welcome the added security of a supple, smart suspension.
Anyway, that's my two-cents worth!