We contacted waterfalls via an advert on righttmove, the girl showing us around was pleasant but knew very little about the property. customer service was excellent until we paid the deposit to take it off the market.
Once you have paid the initial deposit the high level of contact seems to drop off and we were left in the dark a number of times.
We found that they stopped calling and emailing us unless they wanted something, never giving us a call to update us on where the process was. At one point they sent us a full contract with large amounts of confidential data in the post that never arrived (it was not recorded delivery) and the first we knew about it was when we rang them to find out how the drafting was progressing, at no point did they call us to check we had received it or to find out why we had not signed it.
If you hassle them every day and lay out what you want clearly then it all seems to go smoothly, but left to their own devices they will follow "standard processes" which leave you with no idea of where you are in the process.
Personally i found the customer service ok if we rang them but poor in terms of the information they provided us. As with many estate agents the fees are quite high as well.