I own an Avalon M5 and absolutely love it. It is very open sounding and does not color your microphones output as much as some other mic pre's. I have used it on Carole King, Tom Petty, Robbie Robertson, and Natalie Cole to name a few and all prefered it to the other pre's in the room Neve 1073, Summit Audio, Millenia, and Martinsound.
As for the TLM 103 it to is a great sounding mic. I think that is accentuates the high mids but for under a grand you are hard pressed to find another great sounding mic.
I must admit I'm suprised to hear that the combo of a 103 and a 1073 wasn't just as great but in its own way; considering the Avalon, Millenia, and MS are some rather colorless pres compared to anything, let alone a 1073 (I don't know what the SA sounds like though).
Those people that I mentioned were not recorded using the TLM 103. For instance, Tom Petty used a Neumann U47, Carole King like the sound of an AKG C-12. (she has one at her home studio) Both Robbie Robertson and Natalie Cole like the souncd of the Neumann TLM170. I have also worked with plenty of people who would much rather use The Neve Pre's. Most could care less. They just want to see a big silver Mic in hanging front of their face and nothing else.