There IS local storage on the Chromebook. Not much of a file system, but you can put things into the Downloads directory just fine, as well as use a USB drive. It also has a built in Remote Desktop client.
The Samsung Chromebook for $250 remains the best choice. Great battery life(7+ hours in my experience, depending on screen brightness) and very fast. If you're looking for a nice little netbook for basic tasks, it's easily worth it, especially if you're already tied into Google's ecosystem. Best selling point is the free 100GB of Google Drive storage. If you add up the cost of it, it's worth about $120 over the two years it's good for.
As for using it to be productive, Google Docs covers about 95% of people. There are a few more advanced features that some people need that Office has, but as long as you're not using it for complex accounting or anything, it's great. All I need my computer for is A) Games, and B) Programming. It handles everything else that I use my computer for just fine.
TL;DR: If you mostly use your computer for the web and Office, it's a good choice.