Someone up above remarked on my comment about the downside of contacting relatives is to be the recipient of more family lore stories -
Here's an example of a downside - I recently found an 88 year old first cousin to my late father; this man is my oldest living relative who still remembers details of his immigrant parents' lives. I absolutely treasure my conversations with him, and he's opened up a view of my Pennsylvania hometown in the 1930-40s that I didn't know much about.
But - along with these memories, he's related the story from his mother that her family from Gruzdziai Lithuania was descended from a long line of rabbis. I don't have the heart to tell him that I've found two Jewishgen tax records for his mother's father in Gruzdziai. One from 1892 saying he was a day laborer, then another from 1912 saying he had received 15 rubles in poor relief. In 1912, my relative's mother would have been about 10 years old, so I'm sure she was aware of her family's circumstances.
On the other hand, there are more ordinary family stories I have received about immigrants, that I have been able to substantiate with Jewishgen records. One story was of my Shimon Lev/Simon Lavine great great grandfather running a small turpentine operation in Lida, which his relative Ephraim Lev took over. In the 1888 Revision list for Lida, it has Shimon Lev and family living in a tiny village outside of Lida called Iazovitsa (most likely Jantsevichi Belarus). This makes sense, since turpentine is made by distillation from pine tree wood, so it would have to be done out in the countryside. Then in a 1929 Lida business directory on Jewishgen, it shows a E. Lev selling greases and lubricants, which would be a byproduct of turpentine manufacture. I strongly suspect that E. Lev is Ephraim Lev, cousin to Shimon Lev.
I may be in the minority, but I am perfectly comfortable with my immigrant forebears being ordinary working class folks who did the best they could under difficult circumstances. I much prefer to find records that substantiate their ordinary lives, then bemoan the fact that I can't find any records about rabbis or Sephardic ancestors or the fabulously wealthy.
Lock/Lak/Lok and Kalon in Zagare/Joniskis/Gruzdziai, Lithuania
Trisinsky/Trushinsky/Sturisky and Leybman in Dotnuva, Lithuania
Olitsky in Alytus, Suwalki, Poland/Lithuania
Gutman/Goodman in Czestochowa, Poland
Lavine/Lewin/Levin in Trenton, New Jersey and Lida/Vilna gub., Belarus