As a buyer, I much prefer this sort of auction as it allows me to take an overall view of the lots and bid accordingly whereas on a lot by lot basis in a normal auction, once a lot has gone you have no chance to go back and increase a bid when you realise that you could and should have bid higher. As a seller, like Matt says, I've no idea of the size of audience for Colin Cooke's sale but suspect it may be smaller than the big auction houses.