From the customer care side of it, responsiveness matters a lot in the enterprise world (and the non-enterprise world as well). Even if a very complicated issue takes 3 months to fix, responding to an email or opened ticket within an hour and keeping continuous communication with the customers. I have seen customers happy when an issue takes 3-6 months to solve because the person helping them talked to them every couple days asking for more info or giving updates on the the progress. At the same time, I have seen customers mad as hell because the initial response to an new ticket took 3 hours enough though the it was solved 15 minutes later.