@MattKing can you offer advice for all 3 versions of the "new" HC-110 anyway? When I was shopping for one I googled my ass off. Found numerous threads here and I do not recall any kind of consensus. My recollection is: everyone is eager to share their thoughts, but not too many are actually making photos, developing/measuring/comparing. As far as know, there is not a single person on the internet who developed the same scene in different types of HC110 and compared them. Nobody cared to compare HC-110 and Ilfotec HC either. Lots of talkers. Not enough doers.
Did you personally, or someone else here, developed the same film in all variants of HC-110? If so, which one is the best?
My dry plate manufacturing relies on HC-110 dil B as the standard developer for generating characteristic curve of test exposures for each emulsion batch to ensure batch-to-batch consistency. I’ve thus developed hundreds of contact exposures of calibrated Stouffer Wedges since 2017, using both new and old.
I also tend to stretch working batches of HC-110 dil B as long as I can, often discarding the mixed developer when its lost half its volume just from carry over of developer retained in the emulsion layer.
What I learned from doing exactly what you state no one has done is:
1). The old syrup version retains consistent developing (measured via densitometer) for at least 4 months as a working solution stored in amber glass Boston round jars. Contrast appears to slightly increase as it ages, but I never tested that directly.
2). The newer post-2019 variant lasts no longer than ~6 weeks mixed dil B and stored per above. When exhausted it loses its ability to develop, resulting in significantly thinner lower contrast plates. The effect is not gradual in use.
3). Aside from these limitations, I could measure no discernible difference between old syrup and newer when they were fresh. I have not tested the even newer “Made in China” variant.
I have no desire or need to use the Ilford version, so have never used it.
My darkroom and dry plate production is currently packed up after moving out of NH, but I hope to be back up and running sometime in 2023.