That's pretty much how Medion (Microstar) supplied my mother's PC. A good method!
My own self build is divided also, 40:30:60:20 in RAID 0 (which RayUk helped me set up). That's Windows and programs which need to run fast; other programs which can run slowly; media files (music, video etc); and my documents including downloads, drivers etc.
You remind me I also need to back up some of the downloads... I'll get around to it one day. (Just Battlefield 1942 downloads and game demos to save really.)