We moved into our home three years ago and finally got around to getting the ducts cleaned. The tech who performed the work, Shahid, was very professional, diligent, and thorough. He explained the process before starting the work, and then methodically worked from top to bottom. He showed before and after pictures to confirm our ducts were due to be cleaned.
I didn't shop around -- I just wanted to deal with a reputable company; which is what I got with Ontario Duct Cleaning. I will use them again in the future.