Emperical Audio Mods for Parasound Halo JC-1'S

Has anyone had their Parasound Halo JC-1 monoblocks modified with the $1,800.00 Emperical Audio mods, or heard ones that have been modified by them?
If so, how did they sound, and what all improvements were there over the stock factory JC-1's?
Was it a big improvement, or a so so improvement with the mods in place?
In your honest opinion, are the sonic improvements worth the $1,800.00 asking price for the mods?
All information and opinions would be greatly appreciated.