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?
12hz
Thanks everyone for your useful comments. Ultimately I wasn’t looking for suggestions as to which phono stage to upgrade to, as I’ve done research ad nauseam and landed on the Manley Chinook Special Edition MK II. The Gold Note seems to have a lot of loyal fans, but I’m pretty firmly committed to the idea of tubes along my entire signal path. (Also, with the external power supply, the Gold Note ends up being substantially more expensive than the Manley.) That being said, the overwhelming enthusiasm expressed by everyone about the upgrades you all have made has me thinking that this would be a good move and money well-spent. Again, thanks for your comments. 
The Chinook will be a nice upgrade over the Tube Box and you should be very happy with it.
bpoletti:
Save your money and get a Herron Audio VTPH-2a. No need to upgrade when you have the best. The Herron is the last stop on the upgrade path.

Back when I was researching phono stages I came across a lot of comments just like this. Also more than a few deriding or mocking for being so up front about it. Now that I have one though I have to say, its basically true.

In fact only reason I can think of to qualify it with "basically" is there are people like the OP who have preferences for things other than pure sonic upgrades. The OP has his mind set on all tubes. Others have their mind set on features. Or whatever.

For those with their mind set on music, and especially for those musically minded listeners willing to listen and decide for themselves (hardly any reviews, Herron doesn't hand them out, you have to BUY one!) there may well be no better choice.