Things are going well so far - I am using Grant Shipman's model (LivingSmith) instead of padsplit, which works great for me.How nice are the neighborhoods you invest in? 

With  one property, a hotel that doubled as a homeless shelter one neighborhood over shut down and has caused problems for the surrounding areas.

You'll get a feel for the age of the neighborhoods, the vitality of the commercial buildings, the ease of location, the closeness to jobs.The markets you're describing are more linear, and usually have lower capital appreciation.

And still, neighborhoods can change, tenants can go rogue, things can break etc.I'm always looking for ways to help protect investors so I'm open to any ideas you have.

Recently a duplex came on the market that I am really interested in, it is located in an A neighborhood.

I wouldn't consider it a heavy negative unless the street is super tight and parking is hard to come by or if the street is very steep/busy.The more desirable dense city neighborhoods it's almost kind of expected and off street parking would be considered a luxury rather than a necessity.If you get out into the suburbs I would say it's more of a big deal since more rentals have off street parking or a garage there.

Will you continue to buy in that neighborhood with your next purchase @Teslim Salami?

People don’t want to share their quiet neighborhoods with renters who don’t value peace and quiet and a sense of community.  

This means understanding the neighborhoods, pricing trends, and what buyers are looking for.

Find someone in the neighborhood of your building to help you out.