I had a bad experience with Bill and switched to a different accountant.
William Popkin made a mistake on my taxes, which isn’t that big of a deal because mistakes happen.
The problem was the follow up.
I had to contact him a few times for the process of fixing both federal and MA taxes, and each time I contacted him, it took him a long time to get back to me.
It wasn’t an urgent situation, but taking more than a month to respond (even after followups) is unprofessional.
He did eventually fix the mistake, but it was a painful experience.