Marseille runway 31R has a 4 degree glide slope and the 737 doesn't have a problem with that as long as you configure nice and early. The majority of aircraft are not certified though to do autolands from approaches steeper than approximately 3,25 degrees. So a 4 degree slope might not be very practical for larger airports like LHR, LGW en STN since they operate quite regularly to CAT 3.