I never understood re-commercializing the 650B wheel either. Between the 700C amd 26" Mountain wheel, of which there are unlimited types and configurations (tires and hoops) for riding on any surfaces short of on water and, under most any condition, all bases appear to be covered for both large and small riders.
My advice is to reach deeper in your pocket and get the Atlantis. It'll come with 26" wheels, will be tour good and not care about load, it will ride good, it will go about anywhere a mountain bike can go, and it looks excellent.
The Bleriot is a nice bike and, I am sure it rides good and does it's job just fine. But to me, that job is merely cruising around the farm on a niche wheel. I don't know of anything one can do on this bike that can not be done for probably less, and arguably better and with more options, on a 700C or 26" wheel.
Having said that, go for what you want. That is part of the fun. As has been stated, just be sure of 650B availability. Contact people or shops where you will be riding and get real world answers.