I have space for one, but after getting used to the precision of my cnc guy, I think I would be disappointed by a home build...
I've been following CNC forums and information for a while now, and from what I understand, precision isn't usually an issue. Like, at all. You may not get the speed of a professional machine, but I hear that there would be little-to-no loss between machines. If you have the room and the ability to assemble it, I'd seriously look into it.
If I had a building, or even the space inside my house, this is the first thing I would build. First. Thing.