I quite like the 19th ward, with that being said you have to realize that the 19th ward is a huge neighborhood. A general rule of thumb is to stay south of Brooks and defiantly south of Arnett. I agree with a lot of the advice above but I don’t really like the word patchy. There might be a few streets south of Brooks that are less desirable but nothing that I would call dangerous. Once you get North of Brooks is where it starts to get patchy.
Also there are two other neighborhoods in the South West that are often confused with the 19th ward, Plymouth Exchange (PLEX) and Genesee Jefferson. I would stay away from GJ and PLEX, although the extreme south of the PLEX neighborhood isn’t too bad. The new student housing you mentioned is in PLEX and the Brooks landing project which is encouraging.
Heres a good website as well the interactive map is really cool
Home - Rochester City Living