I've used Yopa to sell my property and so far they've been good and my local agent seems to have good knowledge of the current market and my area. I've had quite of lot of viewings and their website is easy to use to manage viewings (as I don't like the estate agent showing people around my house, I can do this myself), it saves me lots of money compared to the typical 1% that high street Estate Agents charges.
The only thing I would say is, the agent will not chase your offers and feedbacks from viewings, you have to do most of the work once the property is listed on Rightmove or Zoopla, which is fine for me.
If anyone wants to use Yopa get £100 discount, use discount code of "willkwan" which you are welcome to use.