The difference I notice between the two is getting more pronounced, Billy is looking for runs constantly, I wouldn't doubt for a second he does more dummy runs then any other hooker in the competition, when Paix comes on he is more pass orientated and his passing is improving, he can get some fast silky long passes out lately which get's us some good edge ball with our halves.
If Kev is giving billy license for the dummy runs I think the fault lies on Walsh to be there in support, if they can work this combination I think it could be a lethal one two punch because Billy's runs lately do seem to have a bit more punch he is getting plenty of half line break chances just with no one available for support in the same postcode.
It does look like he is just doing them and it wasn't to script though, which I think is something the coaches have to look at if this is the case, not because he shouldn't be doing them but because there needs to be organised support for when it happens, many tries can come from those plays.