Jsala,
My speakers are not very efficient either, Spendor 1/2e, but the amp is getting the most out of them now. After some initial issues with break-in, I think the Joule and the D-225 work nicely together.
I am using the CRL Silver on my transport and the D-225 amp. I have a Virtual Dynamics NIte II on the preamp and I use a VH Flavor 4 on the DAC. I was thinking about going with all CRL Silver power cords as I don't experience the thinness you do. Obviously everything is system dependent, but I hear the CRL Gold will deliver more, especially in the bass, maybe that would be better for your system. I do like the VH Audio cables though, great price for great quality.
What tubes do you use in the Joule, I'm thinking of experimenting.