ps audio hca/pca upgrade

I have a ps audio hca/pca combination running Von Schweikert VR4 GenIII speakers. If i want to upgrade, would I be better off with HCPS for the PCA or a mod for the HCA(RAM or ASi)? Looking for increased soundstage and depth. Thanks
PS Audio is coming out with a completely new line of amplification products within the next month. Perhaps buying one of the new amps like the GCC-250 would be a more effective way of increasing performance rather than modding your current gear. The PS website has more info...
That still leaves me wondering whether I should upgrade the HCA or the PCA, if I can only afford one.
Now that they are coming out with a new line, you can get brand new PCA's for $1k. How do you like yours?
I am happy with mine but I sure would like to hear from people who have the hi current power supply and see what kind of difference it made.