My first "Nihonto" was a fake, I was basing my judgment on few books only and I failed. I learned that hard way by presenting my "Nihonto" to other collector. Much have changed since then, due to more books, looking at real Nihonto in others collection (at hand), buying first few with a help of experienced collector.
I think these are a good alternative for Iaido/Tameshigiri. Even for display for people that can't afford Nihonto. I personally use Chinese blade for training (both Iai and cutting), mounted in Japanese Tsuka. Chinese/Thai/other still make that fat oddly looking stake alike Tsuka, not to mention poor wrapping.
Why I use Chinese blade? I don't care if it gets chipped, bent, catches rust or whatever. I don't even clean that blade. Still, it took me a while to find a decent replica, in a way of handling etc. And it isn't (although they are good) Hanwei.
As for these 'high end replicas', I think they are still cheaper than new (not second hand) Shinsakuto with Japanese Koshirae.