As JewishGen Director of Ukraine Research, I too was fortunate to be given a preview tour of Miriam Weiner's Routes to Roots Foundation greatly enhanced website. There is so much that is new and easily accessible -- including links to scans of some original records. After my tour, I searched for particular information and found some helpful data.
There is no other source where one can find which archives have particular records for a town. I have used this feature regularly for years. And it's so impressive that Miriam continues to update it.
Mazel tov, Miriam -- and may you have many more years of updating !
Phyllis Gold Berenson
Director of Ukraine Research for JewishGen