Was able to ride a Walty custom last weekend with Maxxis tires. Felt fairly sluggish on pavement and gravel but came alive as soon as I hit singletrack. Despite the protestations of 32"-fans right now I don't think the geometry is there. It needs to be different enough from 29" geometry that we're a few or several rounds of iteration away from good geometry.
Riding the bike also made it clear that the bigger wheel size is much more scalable to gravel bikes than MTB. That is, the geometry and fit can be made to work with gravel easier and for a wider range of riders than MTB. We'll see if the consumer base has the hunger for a completely new wheel size. This is clearly going to be a years-long campaign, so many things to see in the future.