Man, you are really into Grado!
Now that I am finished buying for a while (he said with no sense of authority at all), the line-up currently sits at (there is overlap):
The iFi is AMAZING with the HiFiman HE6se V2's, T60 Argon's and LSA HP-2's.
The Grado's, of course, like the bass boost of the iFi, as do the LSA HP-2's, but they both sound so sweet out of the Violectric V220. As do the CFA Cascades and Beyer T5's.
My LP is a near perfect match with my Focal Elex's and the HD660's.
1) My LP is probably my least valuable amp.
2) The Violectric has a such a full, warm sound. It is like hanging out with your cat or dog on your lap.
The Pro iCAN is irreplaceable at this point. The only downside is the wobbly 1/4" output in the front. While I do use the HAC system, my Grado's are hardwired and I hate the wobbly connection, but maybe that is just my machine.