How much difference will a phono stage upgrade make?

For the past couple of years I’ve slowly been upgrading my audio equipment. I currently have a Primaluna Dialogue Premium HP integrated amplifier, an EAT C-Sharp TT with an Ortofon Quintet Black MC cartridge, and Tannoy Revolution XT 8F speakers. The weak link at this point, it would seem, is my phono stage, which is a Pro-Ject Tube Box DS. All things considered, my system sounds really good to my ears, but I can’t help but wonder what a phono stage upgrade would bring to the table. I’m looking at the Manley Chinook Special Edition MK II, which is a big step up in terms of cost, but I wonder how much better it will actually sound. Has anybody made a similar upgrade, and was there a marked uptick in sound quality?