Sailors are my favorite pens and I currently use a M and B 1911 full size. I have also used the M/F (Pro Gear) nib and it was too fine for my taste.
I notice a distinct difference between the M and B nibs although both are smooth and wet.
To me (and this is all very subjective), the M feels closer to a Western F and the B more like a Western M and I think that is the question you posed.
Hopefully you will receive some other opinions but I think you might like the B a little better than the M.
I looked into the possibility of buying just the nib section so I could have several nib widths but when I could find a source, the prices were almost as much as the entire pen; in the $150 neighborhood.
QUOTE (zquilts @ Aug 28 2008, 11:49 PM)

I am hoping that someone here can help me decide on a nib size.
I find that the Japanese Fine is WAY too fine for me. On 'Western' pens I like a wet M nib generally.
Is a Sailor Broad nib most like a Medium ? Is there a readical difference between Sailor and Pilot nibs?
Thanks so much for the help !