I have and use one. Similar to what others have listed.
Pros
portable (I brought my used one home in a Chrysler Town and Country) , very stable, no concerns being under car, jack bridges work well for brake work, and can roll under it on my creeper lol
Cons
It is a heavy SOB to move solo. I do it, but I'm not going to say I like it. Non running cars are a challenge. Jack bridge is sort of a pain to have to setup each time, I'd prefer a 2 post lift.
But, at the end of the day, it allows me to accomplish most everything from basic tasks to more complex things such as full driveline removals. I got a great deal on a used one, and haven't quite justified spending for the 2 post.