I ride Perrysville/Perry up as far as the McKnight merge point fairly often; it's not all that bad. Beyond that, just don't. Perry up into the Wexford Flats area is deadly on the main road. Old Perry is a nice climb, but the Flats area near North Allegheny Senior High School is very unpleasant.
Babcock is a mix of beautiful, horrible and not half bad, depending on your latitude. Between Millvale and Three Degree, it's fantastic. The right by the car wash at Three Degree, up to the McKnight merge point (you're actually on McKnight for a quarter mile), is horrible. From the peel-off by Vincentian High School, on north, is fairly pleasant. This is also where Perrymont hits McKnight.
(On a return trip, elsewhere on this board, I've described the Lindisfarne Wiggle, which connects the pleasanter parts of Babcock while avoiding the unpleasant part. Just search the forums for "Lindisfarne". Because of traffic and one intense hill, it doesn't work going north.)
Since I live just off of Perrymont, I know it and prefer it as a cross-street, over Three Degree or Cumberland. Ingomar Rd into NPark is pretty good. Perry to Perrymont to Babcock is much preferable to using Three Degree/Babcock/McKnight.
Going north, Grubbs, just west of NPark, has a long, winding, steep, narrow hill, but isn't bad once you get up it. A R at the end drops you into NPark for a nice ride back on Pearce Mill.
West of Perry, Old Perry (L by the Sheetz beyond Perrymont) to Highland to Brandt School is pleasant but a bit busy. Wexford Run has a squirrely hill near Brandt School but is very nice from there on north. That, to Mingo to Red Belt to Graham to Pearce Mill would make a nice afternoon ride.