As persons have previously recommended, if you wish to learn more about neighborhoods, do some good old "Google" research into past New York Times, New York Magazine, Crain's Business Week, The Real Deal Magazine articles (among others) so you can get a sense of what our diverse neighborhoods can offer.
Good luck in your search.
I have moved many first time home buyers to Harlem over the last several years. Harlem is a big place, East and West and has many exciting opportunities! There are many new developments as well as condo conversions, not to mention HDFC homes!
I would encourage you to work with an agent familiar with Harlem to take you around to see what is available.
Most of my buyers moved there and were new to the area because of affordability and a higher quality of life.
Your view on areas and neighborhoods is refreshing. It is best to suspend judgment on an area, if you are not familiar with the area. Some tend to let their preconceptions or groundless suppositions govern their choice in neighborhood at a significant disadvantage to them.
I myself am not particularly familiar with the areas you mention since I am an agent in New Jersey. However, I have handled many referrals to those areas and have always used Christopher Preto. He is knowledgeable, professional, and a pleasure to work with. I suggest you give him a call. His number is 646-879-6413.
Artyom and Natasha