I test rode the Moots YBB today (26" wheels). I have to say it is the best ride I’ve ever felt on a mountain bike— extremely quickly and agile. Truly wonderful.
I also rode some brand of 29er— the wheels feel monstrous, and the bike felt sluggish by comparison.
What I hope to do next week is to ride the Moots YBB 26" and the 29er, because it’s now apparent to me that a 29er needs a light wheelset to avoid feeling sluggish compared to a 26" wheeled bike. By riding the same-design frame, the variables diminish hugely, and allow the wheel size factor to assert itself, within the limits of which wheels are used.