What's purple bric really like?

I'm looking to sell my house after a miserable time renting it over the last 2 years. I'm finding it hard to trust any estate agents, they all give you politician answers and I'm not sure I trust any of them Does anyone have experience with purple bricks? They seem to be open about the costs and I like they don't take a percentage but with the option to pay upfront does that mean they don't have an incentive to sell? I've been on trust pilot but I've heard the results on there can be fake so does anyone have any real experience? Im in Derbyshire so any other recommendations would be welcome if you've had a great estate agent I'd like to hear