BEAWARE!!!! I switched to a different service provider and haven't had any issues with my elevator since. When we were serviced by Warren, we constantly had to have them do service calls aside for the so called monthly service calls. Every service call is a boat load of money. 2 people show up for every service call (no matter the issue) so they charge you the hourly rate x2. EX: $295 x 2 . They usually make sure to be there for multiple hours. One repair bill accumulated to over 10k without the issue ever being resolved. Try other service providers if you care about your pocket.
Reason I chose to write the review now 2 years since i got rid of them, is because I heard from another person who experienced the same thing we did and it pained me to no end.
The absolute best elevator company in or around NYC. 5 stars isn't enough to describe how good they are. Service guys are all knowledgeable and get things fixed immediately.