They’re still in prototype stage. There’s some videos on the site where he goes more in detail about them though.
I’m going to take a wild guess and say that homologation/certification and health & safety may be difficult hurdles to take at this point in the evolution of exoskeletons. But I expect them to be more and more common as 3D metal printers become more accessible to smaller companies.
As for training... never had the pleasure to try any but I’m guessing this isn’t too different from blade runners. And that’s more a matter of balance than anything else. They seem even easier than ice skating for non Canadians and non Finnish people.