Did you use sweet onions like Vidalia's/Reds/Maui or standard Yellow jobbers? As I mentioned earlier, I use Yellow onions because I find the sweet varieties too
sweet. I also measure carefully, and use exactly 1fl.oz each of Port/Balsamic/Calvados per 1qt stock/2lbs onions. It's easy to add 2fl.oz of one by mistake if just tipping the bottle into the pan when deglazing.
My recipe is different from that of Anthony Bourdain's, but I did add the bacon and balsamic after trying his. Sorry to hear you didn't like those components.
I'm sick as a dog and just had a batch last night. My medicine!