Recently - like a day or two back - I tried installing the Dev Preview. It worked and things seemed fine. But it I also found that I was having problems with the Battery Saver app. Instead of waiting for the problem to be solved, I hard-reset the phone and went back to factory install. Surprisingly, it appears that the hard-reset improved battery life and has made the UI a little bit smoother than what it was originally. I would say that for the L830, I would prefer to keep the stock version (no carrier image for me as I bought it off contract and I have a SIM-only contract) than go for the Dev Preview image. However, on my previous L720, I had the Dev. Preview installed and it did it good.