It depends on the ladder your clan plays on, some don't like it, some don't care. It's not generally considered cheating on public servers but it is looked upon my most as very lame.
In my opinioin it isn't that smart as you have much more control of yourself if you simply use separate lean and strafe keys (using your mouse, for instance). Not being able to lean without moving, or not being able to strafe without leaning would annoy me.
I have seen a topic like this before and... the point of this game is to be realistic...i mean come on, you wouldnt see some Nazi Officer leaning side to side with an mp40 shooting at you looking like a trigger happy drunk :lol: ! Afterall i think it looks rediculous!!! And its very annoying....
Its not cheating. Just like leaning in corners on the building and shooting through the wall. Its just the fucked up part of the game and you all have to accept. I lean-strafe and no one ever complains.