I think that "can" is more like a moderator, not suppressor. Kinda like the XM177E1 attempt to make short barrels less loud (and function better for dwell time). For the amount that soup can moderates, I'd rather have the barrel length because 556 really only has one thing going for it and that is velocity, and the shorter barrels seem to lack the one thing it needs.
Not much of a Knight fan either after having some dealings with the old man Reed, maybe Jr. is better but tree, apple...well anyway.