Update - post Audiofest (06-Oct).
A lot of updates to the system over the past 4 months: (1) the new NiWatt amplifiers, (2) the pre-production prototype of the Eiger rim drive turntable, and (3) all new cabling (some litz cables I'm developing).
All of these developments, in combination with RMAF visitors presented a perfect opportunity to revisit my assumptions.
Well, the short story is that I've gained new respect for the MC stage in the Heron, and it is currently the gain stage of choice. My Air Tight (Tamura) step-ups, along with some very nice Cinemag transformers are on the shelf.
The transformers are close, but in comparison with the Heron's internal MC stage, they don't deal with fast transients as well (a bit of hashy overshoot,in comparison).
Disclaimer: as a manufacturer, I have accommodation pricing to the Heron.
In my humble opinion, the next step up (no pun intended) is the likes of EMIA and Alnic, but YMMV. No association or financial interest, other than knowing Jeffrey Jackson (EMIA).
Cheers,
Thom @ Galibier Design