@atisv99 - thanks for checking in. The bottom line is that I really like the Manley Chinook. How does it compare to other phono stages like the Herron? I don’t know because I’ve never heard one in my system. Going back to my original question, however, yes, it made enough of a difference in sound quality to justify the expense. I have a very low output cartridge (Ortofon MC Black) and the extra 5 dB of gain that the MKII offers seems to be a significant benefit to getting the Special Edition.
I would be curious to hear more about the EAT phono stages if you decide to go that route. I briefly looked into that as an option but for whatever reason I was fixated on the Chinook. (I was interested in the Herron, too, but it was beyond my financial reach.)
On a side note, but relevant in terms of support and customer service, the first Chinook that was sent to me was dead in the water. It wouldn’t fire up at all. After minimal back-and-forth with Kat at Upscale, a new one was express shipped to me and I sent the first one back directly to Manley. Both Upscale and Manley worked to resolve the issue as quickly as possible. Disappointed but not deterred, I waited an extra couple of days to get one that worked, but it was all very painless. The second one lit right up and has been working beautifully ever since.
Thanks to all on this forum who offered useful advice on this topic.