Thanks, everyone, for your comments. I test-rode a Como 4 IGH and a Vado 5 IGH today; the main difference besides frame geometry was manual vs. Automatiq. The Como 4 was almost completely silent; I was very pleasantly surprised. The Vado 5 wasn't loud, but motor noise was more noticeable than the Como 4. I felt very much 'at home' with the Como 4 since I'm so used to manually shifting my Jamis with the Nuvinci hub.
The closest competition now, in my mind, is the Evelo Atlas. But I hesitate to order one, assemble it, and test ride it only to discover that the sound is too much (or some other issue) and then disassemble it, repack it, and send it back. I am considering it though.
I do wish the Prodigy came with an IGH and belt drive.
Thanks again for all the comments, it has been very helpful. I do understand how subjective this issue it, but it also seems that as long as the motor is 'relatively' quiet, I will 'get used to it' and still enjoy the rides.