Honestly, we did it because we were lazy. Which I think is most people. I'm not sure we'd do it again, there was very little value in what they did (a couple of photos, eventual spread in the window [not really sure how effective that would be, but our kitchen looked both nice and uncharacteristically tidy] and upload to the usual property sites) more so considering that even a small percentage of a London house is a lot of money these days. They did get us asking price (and I thought a reasonable asking price).
And like I say, they lost all interest the moment the offer came in. We got half our money back (begrudgingly and with no actual apology). Solicitors were useless too (I think I detailed that story elsewhere). Horrid process, like chewing through curdled incompetence, I have no idea how any of it endures. Well, I do, to extract money. I once had to spend over an hour explaining the difference between verticle and horizontal measurements and three-dimensional topology. I don't think, even with global warming, the local stream is going to rise 73 meters. Yeah, we had to complain about our solicitors too, don't think we got anything out of them on the grounds that uselessness is expected.
The EAs we bought this place from were very helpful (which shouldn't be surprising, yet is).