I found that the Surly Big Dummy was more stable with heavy loads than the Ute, the 26″ wheels and the carrying design seems to keep the centre of gravity lower and make it less prone to the speed wobble when heavily loaded.
I was in Germany last week, so called into Koblenz to test ride the Spectral. Apparently the 29er range for 2016 should be released in the next 2 or 3 weeks according to the salesman I spoke to.