The reason I like big stones is they eliminate one more variable from the precision honing process. Big stones sit on the bench and don't move around. My favorite blue beligan is 10"x4" and that's a great bench stone. I like the smaller stones like the 6" ones or the 4" ones for when I'm moving the stone against a blade I'm holding stationary. I keep all the sizes around as I like to keep stuff sharp.

A few weeks ago I picked up some 6x2 DMTs that are double sided, continuous diamond. One has coarse and extra coarse, another has fine and extra fine. There's also a fine/xtra coarse and a fine/coarse but I haven't played with them yet. These stones are very handy as I don't have to hunt down stones; just flip them over.