I'm looking at purchasing either the M1-L or M1-S... but I'm a little confused. I currently have the NN3 II but I like the idea of the quick release and the better strength of the M1 (my NN3's vertical rail sags a bit sometimes).
The thing is, I like the short horizontal rail of the M1-S (160mm is plenty) but I want the longer vertical rail of the M1-L (also it looks stronger and less likely to sag). However, it doesn't appear possible to get this combination unless I get both larger rails? I don't want a larger horizontal rail because it will just take up more space and won't be useful.
However, I noticed in the 'includes' section that lower rail and upper rail are interchangeable. Does this mean that I could essentially use the 170mm upper rail as the lower rail, and use the 210mm lower rail as the upper rail? Would there be any trade off for doing this?