Yes, unfortunately you don't get access to the desktop application unless you sign up for a premium plan. Also, the file size limits for upload are lower unless you are a premium user. So maybe don't bother, if Dropbox works for you in the free version.

There's a way around it. It's just WebDav.

Here's how to do it on Ubuntu, it works just as well on my Mac: http://www.howtogeek.com/howto/ubuntu/how-to-access-your-box...

Yeah, this really is the best route in most cases anyway. Besides, it's one less thing that you are stuck installing.