I use a 6 wt for small mouth. Mainly because the streams I am fishing are fairly small. Last time I was on a lake for LMB I threw bass bugs on a 7 wt. I found that it throws them pretty good. But there are some casts that I would make longer if I could. This winter, I bought a 9 wt to use for larger water LMB fishing and throwing larger bugs.

So for me it's 6,7 or 9 depending on the water I am fishing and the size fly I plan on throwing.

wayne