Not professionals. Bad job was done both by estimators and by actual workers. It took 10 (!) calendar days to do the job (700-800sf). All imaginable and unimaginable mistakes we made: re-doing a few times due to horrible quality, running out of materials, always appearing 2-3 hrs later than promised, huge amount of dust (so much for the 99.9% dust-free!)... It was 10 days of the nightmare!