I haven't personally used them, but a former BSR used them for a few years. Like no line progressive lenses, some people just never get used to them, and some people have no problems whatsoever. She never had an issue with either vision or depth perception with the contacts.
The brain is an amazing thing...it adapts pretty quickly to things like this, for most people.
I remember reading a psychological perception study back when I was in school where they put glasses or contacts (can't remember) on some people that made everything upside down. After a relatively short time, their brains made everything right side up again. Of course, then they were messed up again whent the experiment ended...
Either that, or it was that acid I did....