I really enjoy singing, i love to sing online too, especially with all the staying at home. On that platform people always ask me "are you singing in a box?" And then they ask me more info when i explain its purpose.
I live in a appartment building from the 1950's, the concrete makes sound travel further than you want it too. My neighbour below complained and the others knew i sang. That is a bit awkward and inhibited me a little bit. Especially if you want to do scales, that doesn't make you friends anywhere anyway.
Enter the Isovox: to start with the downside, its not ideal to do a 1 hour scale practicing session, because it will get a bit warm inside. However, if the alternative is angry neighbours it can be a real lifesaver.
Also, i record a song or two, and then open the flap for some air, and doing this i can stay in there for a long time withouth being bothered. I sooner get tired of standing up than of the box life itself.
The isovox adequately dampens sounds, i would say you are still quite audible but it take the edge off. Say that if you heard someone sing loud in the other room, now it would seem like a (loud) conversation. (maybe the worst 40% volume is gone)
But dont let me convince you, listen to my 80 year old neighbour lady below, she said my singing bothered her. Now, it doesnt anymore she told me. Now, in order to please her more i should probably need to buy a silent guitar as well and some carpet ("you drop stuff")...
About the Isovox itself: it is well built, quite beautiful (mine is white) for what it is, also on the inside. It is kind of massive but i like its looks enough that it does not bother me. My cats havent abused it yet, in 5 months, so that is a good sign as they destroy everything else.
Make sure you get a nice stand, the one included in my thomann package was so-so (millenium) as the twisting lever in the middle broke and now it is stuck at a certain height.