A. 5 Star Drain Cleaning: He was on time and professional. Drain was cleaned quickly. As this had been a recurring problem, he suggested replacing cast iron length of drainpipe w/PVC. He also recommended a vent for better drainage. I agreed to the price, and he returned to do the work a week or 2 later. B. 1 Star Plumbing: Preface: He was about 4 hours late, and arrived around 2 on Friday, appearing frazzled. Also, being in the midst of pandemic, I left him alone to do the work, to limit contact. So, I did not inspect the work til problems surfaced some weeks later. Problems: 1. Vent not installed: After he finished, I asked him where he put the vent. He said I didn't need one, in spite of him including it on the proposal, & stating again he would install one when he came to do the work. There was no price adjustment for omitting the vent. The remaining items below were not disclosed to me, and should have been. 2. Blocked electrical outlet with new pipe: He only partly removed the old cast iron pipe that ran from the basement up to the sink, leaving broken pipe remaining. This blocked the space needed to run the new pipe. As a result, he had to drill a new hole for the new vertical pipe further into the cabinet, as well as using more horizonal pipe below to reach the new riser hole. (I believe this made the vent much more difficult to install, and that is the reason he didn't install one.) He also placed the new drain riser directly in front of an electrical outlet, blocking the electrical outlets for the Instant Hot and Dish Washer. (I don’t use these regularly to save energy so did not notice this problem for a couple of weeks.) 3. Inadequate pipe support: He reused the old, rusted iron strap hangers, instead of supplying new ones. However, because of item 2 above, he had to use an extra length of horizontal pipe to reach the new hole for the drain riser, and therefore that section of pipe had no hanger. As a result, the pipe sagged, and several weeks after work was completed, sludge started coming out of the under-sink cabinet. The new vertical pipe connecting the sink & disposal to the sink above had separated from the compression fitting. In addition, the horizontal pipe in the basement had sagged into a V shape, slowing drainage. Due to my reduced workload from pandemic, I could not afford a plumber to repair the pipping. After cleaning up the sludge, I jacked up the piping in the basement. And put a stack of phonebooks under the short horizontal pipe under the sink to provide temporary support to keep pipe from slipping from the fitting again. Conclusion: He did a good job at a fair price, cleaning the drain, and at short notice. For future plumbing work, I will contact a licensed plumber. Mitigating factor: I believe he had a difficult day, arriving late on a Friday, with I'm sure more pressing family obligations. However, he didn't disclose the problems he encountered doing the work. And I ended up with a mess I had to clean up, jerry rig, and at some point will have to pay a plumber to repair.