A great home
Pros
The building (and apartment) is the best one I've lived in since moving to New York over a decade ago. Great location (very quiet), kind neighbors, and fairly responsive management. The current management is a lot better than the previous management company. All things considered, very few problems overall, which is a blessing in NYC.
Cons
It's on the older side and it's a walk-up. The current management updated the main entrance a few years ago, but the stairwell and lobby could be renovated and could be brighter. The apartment could be updated to a degree too. We've had bugs over the years, but it's NYC, and has been nothing too serious, thankfully.
Advice to the owners
Not much, keep being responsive to tenants' needs, as you have been.