I would agree that roe can be "lights out", where wool - not so much.  However, I've had cases where the fish will take wool and only a certain colour or even shade of colour produces.  I've even gone down to 6 lb fluorocarbon leader on a small piece of wool and caught the odd coho, where the same presentation on 8 lb leader failed to work.  That tells me that the fish can and will take wool, but I don't believe they'll chase it down (I've had nice coho chase my roe while I'm reeling in - and actually caught a few that way).  For those who think that you can ONLY floss coho with wool - I'd have to disagree.   Yes, wool is often used to floss fish (Tamihi is a prime example of where this happens).  But wool can work under certain conditions.  Just don't expect a fish on every cast.