Worth it to try a SUT with a 103R and Herron VTPH-2?

If you're married to the 103R, my vote is also upgrading the VTPH2 to a 2A.

FWIW, I'm using a Hashimoto HM7 SUT into a VTPH2A.

I’ve started using a Sky 20 with my VTPH-2A. The JFET MC stage in the Herron is really good, so it’s much closer than usual, but in the end I prefer the extra warmth and fat tone lent by the SUT, especially with Shelter and Koetsu. It’s notably more vivid and alive sounding, at a very slight expense to the ultimate refinement and resolution; the trade-off works for me. I’m a big fan of SUT’s. In the main rig I use an EAR MC-3 which beat the Sky 20, but I haven’t yet tried that EAR with the Herron to determine if it’s a good pairing (probably would, though).

This is all GREAT info. Thanks all!