You wouldn't buy my house then, MidniteScribbler, because I do the showing around. It would be highly inconvenient to keep going out. It is nothing to do with negotiation- that goes through the agent afterwards. I merely do the tour. Since it is my house, I pay the agent, I get to do it my way. Agents are never as good as the owner- they haven't lived in the house.
No, I wouldn't buy your house. I don't want to know your opinion of the house, the neighbourhood or the neighbours. You want to sell the property, so I'm going to consider you about as trustworthy as a vacuum cleaner salesperson. Most vendors make very bad sellers.
When we sold our last house our daughter, who was two at the time, decided to show one set of viewers around.
That would piss me off no end. I don't want to have to play nice with your toddler. I went to one where the owner insisted on staying and a child would not leave me alone. Driving me crazy. Then I find out he has chicken pox. I walked out and refused to even consider that house.
I've bought and sold 34 times, and never once have I dealt directly with an owner of the property, rarely have I even met them. Fortunately, it's not the done thing around here (except for the idiots who think they can not use an agent, and I won't even look at those properties because inevitably the owners are always delusional about how much their house is genuinely worth).