On the flat areas, the corners were true, the gaps even so the contractor was reasonably proficient. The first contract was completed without a hitch but on the second contract, 2 things that happen that I think are inexcusable. They dumped the waste water from the grouting into the toilet. They may not have caused the clog but at a minimum exacerbated the problem. The waste water backed up into a brand new acrylic tub. Secondly, they never checked the floor for level. The main part of the bathroom floor was level but around the toilet, the difference between the front and back of the toilet was more than 3/8".