I have one of the 'SE-Type' vocal booth things that sit on the mic stand....
It's been working well in the room I've been using but took it to a friends room and we really struggled with it, ending up in its abandonment...
I'm in the process of building a new room in the attic (insulation arrives in the morning) and I'll try it in there and see... The plus is that to a certain extent I'll be able to do more in this room in the way of treatment...