I have a Samsung Chromebook and, although it's quite convenient, I found that there were just too many times when it couldn't do what I wanted it to and I had to resort to a proper PC.
Have a think about everything you do and consider whether you can do it in a web browser, because at the moment that's basically all they are.
A few things I found issues with were
downloading files (bittorrent and NZB),
using Office (I can't really get on with Google Docs but this may not be an issue for many),
playing video files (you have to use their video player which isn't great and it seemed to struggle with some formats),
playing music, there's no easy music library like winamp/itunes (although if you have a network connection the google play music is fine)
printing, it wouldn't work with my wireless printer
USB peripherals, it can cope with mass storage but anything more complicated is hit and miss.
It's definitely not a replacement for a main PC, as a secondary PC for web browsing and nothing else it's OK, more of a tablet replacement than PC replacement.
I have a Samsung Chromebook and, although it's quite convenient, I found that there were just too many times when it couldn't do what I wanted it to and I had to resort to a proper PC.
Have a think about everything you do and consider whether you can do it in a web browser, because at the moment that's basically all they are.
A few things I found issues with were
It's definitely not a replacement for a main PC, as a secondary PC for web browsing and nothing else it's OK, more of a tablet replacement than PC replacement.