I have an Acer R13 Chromebook and am delighted with it.
Pros:
Inexpensive, butat the time I bought it, the bottom end of the Windows PCs were a similar price.
Compared with tablets the keyboard is a big plus.
Good screen with touch operation.
Built in apps are good and supports android apps.
Metal case, slim neat and looks classy. Also folds for a "tent" display or right over to use as a tablet.
Good battery life.
Cons:
Only 32GB internal storage, but has a micro SD card slot and the Chrome operating system facilitates storage in the Google cloud.
The concept of having office files automatically stored in the cloud takes a bit of getting used to, but you can store locally.
No ethernet socket, so must have access to WiFi for internet access.
Good battery life.
When folded over to use as a tablet it feels thick and heavy compared to a genuine tablet.
Can it replace a PC? That depends on what you need to do. Internet browsing, e-mails, writing documents, spreadsheets, simple photo editing, playing sodoku are all fine.
Hope this helps.