Hey @xmachine
The parametric pro eq was in development at the same time as the old free version and is a complete rewrite of everything.
When Spotify then switched things up and broke the old eq i had to decide which version to spend my time on, and i chose the pro version.
Like @DigidyDOG said, the old free version does not work with spotify 1.0 or above, the only way to get it is via some random download site on the net. You will also have to downgrade to one of the 0.9 versions of spotify to use it.
The old UI is gone and will never come back. What might happen in the future is a 10band preset that will have the Q and Hz locked so you can only move the bands up and down. That will behave pretty much like the old EQ but in the new GUI.
When making your presets, remember that you do not need 10 bands to get the same curve as the old 10 band eq showed… You will most likely only need 3-4 bands. The white line is your effective filter and is what you should focus on getting how you want.