they look exactly/close to the same, and same build (without the kipon name).
leica m-mount is only $25.90 (compared to $71 of the kipon counterpart). to be honest, they just look rebranded and of the same quality. the only difference i see is that the m-mount adapter has the ridges around the adapter, and the kipon one is smooth all the way around. the contax g adapter looks exactly the same though.
from a description from another seller, these are made of aluminum (in contrast to "brass" as stated from Kipon).
with the history of bad experiences of cheaper Contax G mount adapters for the NEX system, i would stick with Kipon for those (since that's the only mount that uses a focusing mechanism in the adapter itself).
as for other mounts, i really don't see how they can be "bad" if it's just a copy of kipon's.
It's startling how much this camera reminds me of a black Contax G2. Much has been made of the Leica look but it truly feels like an autofocus Contax. Even the OVF focusing system is kind of what I fantasized about while trying to focus with the G2.
I'm glad to say that I've had no scary moments, with any of the cheap adapters that I've bought for either Eos or M43. To be fair, though, they're all very simple bits of machining, with nothing more elaborate than a locking tab for the guest lens (Leica M and Nikon).
Sometimes out of focus but never out of bounds...