I grew up in Kensington. Back then we just called it Kensington. But that's a whole other story.... Check out this web forum.
You can browse recent posts there and also create a user name and ask people who live there what they think of that particular block and area. Philly's neighborhoods can be block by block, but you still have to walk through other blocks to get anywhere so... listen to your instincts. I always recomend to any buyers I have to do drive by's at all different times of day. Now that it's warmer out you will see a lot more people out. Check out the neighborhood when kids are coming home from school. Check it out when people are coming home from work. Check it out later at night like 10 or 11 to see what's going on in the neighborhood. What you see and who you see out will give you an idea of what is going on.
Let me know if you would like a recomendation to a realtor in that area. He grew up in Juniata and now lives in Fishtown and sells real estate exclusively in the Fishtown, Port Richmond & Kensington areas for Prudential Fox & Roach. He's fantastic and I'm sure would love to help you if you don't already have an agent.