I don't really know that I'm even going to spend much time farming in New Haven anyway, just thought it was something interesting that I found. If I take advantage at all I'll probably just do it long enough to get a new shield (since I've been using my current one for forever even though it's not all that great because I've gotten terrible shield drops) and a good revolver (because I like those a lot for some reason but, again, have only found pretty crappy ones).
Once you get to the second playthrough they will be plentiful...but revolvers are pretty useless it gets way hard!