Just a comment: you can also use tags to group project items together, instead of sub-tasks. This is particularly convenient if you are otherwise including an abbreviated project name in the task anyway. So you can use contexts, folders as areas of focus, and tags for project names.
Yes, that's a good point. Toodledo is quite flexible and can be setup in many ways. I run it in multi-line view so I don't see contexts or tags in my lists - I use them but just don't have them visible all the time.
I'm using tags for areas of focus and folders are my GTD status (next, waiting for, etc).