Tooling is a big boon with TypeScript: Go to Definition, Find All References, Refactor->Rename, debug your TypeScript in Visual Studio.
You're right that if you don't use the tooling, TypeScript is of lesser value. Using things like classes, lambdas, modules syntax is still there, of course, and is quite a bit nicer than JS equivalents.
Be careful with that if you use data-binding in your templates, such as Knockout.js . Visual Studio doesn't know the types of your viewmodels, so those templates are not indexed and not subject to refactoring.
You're right that if you don't use the tooling, TypeScript is of lesser value. Using things like classes, lambdas, modules syntax is still there, of course, and is quite a bit nicer than JS equivalents.