Weight and shaft profile depends on how fast your tempo and transition is and if you are a hitter or a swinger with early or mid or late release. Flex in and of itself IMO means nothing.
Example, I am using a "R" Vizard 53g 45.50" in a Honma XP-1. Most shaft manufacturers they would designate it as an "L" flex. If I get quick and rush from the top it is all over. If, I am my usual smoother tempo, full turn and 1.4 second transition time it's great goes where I want, as I play it a high draw and goes far. It helps that I took it to my target MoI heft match.
