Well I had it on for only an hour but as it does deliver about 4 novelties at the same time the experience is one heck of a thrill ride, essentially Rift versus monitor is the difference between controller+TV and a racing cabinet, doesn't seem like a big difference when described but the experiences are miles apart.
Because you get full vision coverage and 110° of that being the actual image (compared to 20° for a couch + TV view, or 55° for desk + monitor), on top of that proper 3D with separate images for each eye, and most importantly real time head tracking makes it feel like you are actually standing in the virtual world... so much in fact that you need to be sitting or your will seriously hurt yourself.
All that being said however this is an early prototype, it is very expensive (looking at $500 for the quality release), has lot's of issues setting things up and games do need to be specifically reworked before it functions even half decently, not to mention standard 2D UI doesn't work with Rift and head tracking is an extra input which games do not even consider at this point.
Also this screws with your vision and orientation like nothing we have seen before, after an hour I couldn't even stand for ten minutes, try using it for several hours and this is sure to cause some serious nausea not to mention what it would do to your eyes in the long run.
Wouldn't call it revolution but it certainly is a very unique way of experiencing a virtual world, probably not advisable for the average user at this point but still very functional.