Clemenza, you are talking to a life-long resident of Union Co. I once lived in Linden for 7 years, Elizabeth for 25!!! Unequivocally yes Linden was far better 20 years ago, before the immigration flood. Besides, most of the immigration I see in Linden has always tended toward Polish/Slavish. For decades Linden was 1 and 2 family homes, blue-collar, a nice place to live. Now I see lots of Apartments going up near the center of town and I'm sure things will take a turn for the worst---just like what happened to cities like Elizabeth and Paterson a generation ago--lots of big city problems, welfare, crime, domestic violence, etc. the kind of things that rarely ever happened in the past.
Only parts of Union County that have gone from ho-hum to bad have been Roselle and Hillside.
Summit and Cranford looked great last time I was there. I understand Scotch Plains is, for the most part, the same. Other than that I have always thought of Union County of being filled with pollution, crappy (by my standards, I'm a bit of a snob) neighborhoods, and the corruption that Jersey is noted for.