I can only say I do know a few who have bought from them.
However when I was looking for a lorry I spoke to them once about a lorry on their website, it was sold so he took my details, what I was looking for, etc.
Never heard from them again....? So I assume everything sells really quickly as I'm only 20 miles from them and could come and look at short notice. Bought privately instead.
I used them as a broker to sell my 7.5 tonne. I was asking £35,000 net of their fees for it. They arranged a driver to collect it and I paid him directly as agreed. Once they had it they asked if they could repair some paint damage for which they provided a quote. I agreed. The box sold really quickly but I had to ask for my money. They had charged me for cleaning (this was not mentioned on their website as chargeable to the vendor and the box was immaculate) and a ramp repair which was not discussed with me. I was annoyed and we came to an agreement about it. I would use them again but would have factored in these hidden charges when agreeing the price I wanted to achieve.