As some others have said - try to avoid those that could clearly be problematic and I'll add that the ideal buyer has cash and no chain. Full stop. But they're a rarity!

Moving house is so stressful you want a buyer who is not going to mess about or pull out last minute, though it's very difficult to know what they will actually be like. No chain at their end always adds a little comfort in being less likely to fall through.

I couldn't care less who buys from me and you're just creating more opportunities for problems by trying to be nice or favouring someone you perceive to be 'better'. You'll never truly know them.

Do you do the same selling your car or furniture? I very much doubt it. Same thing here, and some given the money involved.

Talk factually to your viewers is my advice. Don't try to please, the facts will do the work for you. If it's not right for them they'll be more likely to pull out if you manage to twist their arm! Bear in mind, most viewers will be lead around by an estate agent most of the time so give them space and time to amble about a bit too.

As a buyer I don't care what the seller says. They'll always be trying to make it sound great, but that's not necessarily 'bad', just biased/selling talk and as a seller you'll do the same instinctively. I get a survey done and view the house with my wants and needs in mind, something the seller will largely be oblivious to, partially as viewings are more often done with an estate agent rather than owner.