Best managing agent?

I recently listened to a rant about how X is the worst managing agent company. I thought this was interesting in light of the fact that a few weeks earlier, another couple, with obvious resignation, explained to their dinner party guests that their managing agent is worthless (conversation prompted by noise from the unit above that was marring their dinner party - sounded like slumber party playing soccer hosted by family that is apparently flagrantly flouting the 80 percent carpet rule). Is anyone happy with their managing agent or is it another given of living in NY that managing agents are worthless? Are Elliman buildings viewed as better managed than Brown Harris or vice versa? Should this at all be a factor when looking at prospective purchase?