Went through the process. Added a 8GB partition to my HDD, made a bootable Mavericks installation on it, restarted, pressed Option and chose the installer. Chose the option (I think it was the first option, might have been the second one) to do a "clean install" of Mavericks. It took the whole 45 minutes or so and when it restarted, it had upgraded, not started anew. Is there something else I need to choose while at that menu? Maybe open the HDD in Disk Utility and erasing it? I figured just doing an install from there would provide a clean install, as I'd rather not do it as an upgrade. Any help would be great!