I don't think decoupling it from a computer is going to change the experience much, because you'll still need to be in a prepared safe environment to use it. Until it supports AR or AR-like features so you can deal with the real world in some sense (even if it's with RL stuff automatically mapped into wireframe danger zones or something) it's still going to be "tied down".
It does completely change the experience. Compared to being tethered to my desk literally with a cord on my Rift, I have been able to just pick up and put on the Quest in several rooms of my house. I don't have huge amounts of open space, but even just being able to sit in a chair and use the Quest is a whole different experience, or to lie in bed and use it.
I do have a spare bedroom that is empty, and I was able to set up the layout of the room in about 30 seconds on the Quest and then freely move about to try out some roomscale experiences. The process of drawing the room was incredibly simple, and if it doesn't correctly detect the floor level you just tap one of the controllers against the floor and it moved the grid perfectly. Once using it, if I got too close to a barrier, it showed me on screen as I was nearing it and if I still kept going, it switched to showing me an external view. It won't help if you have a bunch of crap on the floor to trip over, but that is not a tech problem. It also remembers the space when I come back to it, I don't have to redraw it again.
Being able to pick up the headset and just use it, with no computer needed, and have a fantastic VR experience with full tracking is game changing for consumer vr devices. The only barrier to entry is price, but for the experience, $399 is not outrageously priced.