I'm using the 124B (driven parafeed by parallel sections of a 6n1p) as an IT in a single ended 6B4G amp. It sounds great.

Neat trick in the nickel wonder, spinning it around "backwards" like that for a 3:1 step-down...

I think it'd definitely better than specs say in that application because it's rated as a driver xfrmr - at 5 audio watts. Unless you're driving a class B or A2 stage ahead of it, it's not working nearly as hard as that.

TC