Definitely a nice livable neighborhood. Safety problems weren't significant, accept for a lot of homeless dudes just kind of standing around. There's not really foreigners there, so there's not people that prey on them. Decently policed as well. I'd expect the safety issues that Argentines might face, rather then being targeted as a tourist. If you did have an incident, it might be more severe than a snatch and grab or something. I would check the physical security of the apartment itself and not take it if someone could force entry. But in general, no worries. I feel worse in the Microcentro alone at night.
The prices are a bit cheaper than the foreigner neighborhoods, but there is also notably less stuff to do. Cabildo is nearby, but it is really shopping, restaurants and cafes. This was really the downside to me, because I like to be in walking distance of some kind of goings-on.
Coghlan is out there too. You might want to try the bus ride from the places you usually go and ask if you're up for it on a regular basis. I don't know how many times I just didn't go out because I didn't want to drag myself to Palermo.
