I'm guessing a flare tip would be about a 4. Have more experience with the Slim than the flare though.
40s SS would be 5 or so.
I find them to be fairly different beasties from the Slim. Weight and handle length make pushing it around your face much different and give a different type of shave.
My Red Tip is about a 5 on a Slim or a 195 Adjustable, and my 40s Super Speed is about a 4. My Black Tip seems to be about the same as the Red Tip, I've never had either a Silver Tip or a Blue Tip flare.