QtCreator messes-up existing CMake build directory

I work with complex projects, and configuring CMake quite often requires many parameters to be set in cmake's command line.

Previous versions of QtCreator worked nicely with existing build directories. QC 4 messes up existing build dir completely. The only solution is to set the variables again in the - very clunky and inconvenient - project GUI.

This is really a productivity killer. This may work for hobbyist that have few projects, are afraid to use shell and want to click trough the project setup. In professional setup, with tens of projects and configs, and many varaibles required - this just breaks things.

Maybe there should be an easy way to open CMake project with existing build directory?