Hi Sam
all the Twisters have a similar action. F3 and F5 are supposed to be same size with only difference being weight but I have had a F3 that weighed as much as the F5 before so I got a bit confused. F6 is a lot of lure - its 200g+. You'd do a F3 and F5 with a TBL711 but a F6 is a big ask. I think that the BLC, while able to cast both these lures would oversaturate a bit when working them. It'd do it but not ideal. F6 is too much lure.