I've been using Joli OS for roughly a month now. Here's the meltdown of it's pros and cons:
Great simplicity. Easy to use and set up
Goes well with various cloud services, google drive, skydrive, whatever
desktop can be accessed from any browser
Perhaps a bit too cloud oriented. The computer is essentially rendered useless you have an internet connection
I wish that local apps were a bit more emphasized.
The entire desktop is a browser page, kinda slow at times
Overall great desktop. It's really great for old laptops that can't handle new software and need a facelift. This OS seems to have various drivers already built in so you don't have to hunt for drivers. Overall great idea, but maybe it's a little bit ahead of its time.