Cosme is Very, Very nice, with great customer relations skills. I called him early on a Saturday morning due to a pipe connection break. He patiently answered all of my questions (unlike another plumber who was irritated by questions, told me to fix it myself and hung up on me when I asked for an estimated arrival time).
Cosme was easy to reach even though he already was busy with jobs for the day - at 10am on a Saturday, which for me was a sign that he must be good. Being already so busy for the day, he was honest and told me he wasn't certain of an estimated arrival time, but offered to call me later with an update when he had a better idea of his arrival time. He also recommended another company in case he couldn't make it, or if the building wouldn't permit him access for not having proof of insurance with him (because a plumber doesn't have that on hand because it comes from the insurance company, which he couldn't get until Monday, which I knew to be true from having scheduled a plumber for the earlier renovation). He knew the quality of the other company, and knew that they had worked in my building before so there should be no entry problems.
PLUS, Cosme was the best price of the quotes I got that morning. Great pricing, Excellent, friendly customer service, and Honesty; that combination is rare in most any industry.
There was a mix-up due to my tenant calling for estimates also, and another plumber was able to arrive sooner, so Cosme didn't do the work.
However, Cosme is now on my vendors contacts list, and I know I won't have to quickly search in the future; Cosme is the First person I will call when I need a plumber, and I will recommend Cosme to everyone - and already have.