I haven't used it for anything particularly complex and I haven't used it with anything that has a ton of non-header-only third party libraries, so I don't know

I haven't used it for anything particularly complex and I haven't used it with anything that has a ton of non-header-only third party libraries, so I don't know how it holds up in those cases, but for my smaller projects, its been really pleasant. The tupfiles are easy to write and the tool is super fast. It took me from dreading starting a new project with cmake to enjoying using C++ again. I used to just use QtCreator and let it setup the build system. I could just go back to that, but for now I'm very happy with tup.