While on the whole they're good quality cups, I find that two of my cups nest too tightly, meaning
they have a tendency to "stick" together. For the most part this doesn't matter, but for the "ball
passing through the cup" move (sorry - I don't know the correct title) it's a problem.
Perhaps I was unlucky with my set and most sets are fine.
Aside from this though,
they're decent basic cups, though they do also tarnish like crazy (as has been said already).