I bought a lens2scope.
Yes , it works and with a 200 mm lens the moon almost fills "the frame". Furthermore, it is sharp enough for bird watching at significant distances, let's say half a mile
1) Biggest drawback is the focussing. With an EF-S lens such as the 18-200 kit lens it takes a very steady hand to gently turn the focus ring to get focus. I tried it with a an old 100 mm macro L lens and the issue disappears as the focus ring is a lot better
2) in bright light, chromatic aberration is visible through the viewfinder
Would I recommend it ?
If you have a lens that you do not use anymore and you want to have a scope for 200$, then the answer is yes
If you plan to use it with a new L lens that you use in everyday life on your camera, then the answer is no. There have been other reports of damaged electrical contacts, which can happen if you are not carefull during the mount.