I was pretty surprised that OpenGL performance was so bad. If that is in fact the case then that could certainly affect both productivity and user experience in certain scenarios.
In general, there was very little written about the performance of Snow Leopard on traditional benchmarks when it was released. Most of the comparisons were to previous OSX versions based on boot times etc.
However, Leopard's poor OpenGL performance was noted at the time of its release (but generally drowned out by the choruses of "it feels faster" from the echo chamber [see http://www.google.com/search?client=opera&rls=en&q=s...].