I knew I should have added quotes around that usage of "upgrade" too! LOL! Guess, I'm feeling older than my age or maybe younger! Again, individual perspectives and tastes will vary. I was just going with the Viking terminology. All I know is that it went really, really well with the chocolate desserts it was paired with for my taste. Yes, port and chocolate pairs well, too. But as I already mentioned I'm not a big fan of ports, so for me this was the type of experience I was looking for at Chef's Table. And, yes, we have found wines on the included list that we liked better than some on the SSBP list - but that's how it goes with wine and individual tastes. The SSBP just gives us more options to choose from in my opinion thereby broadening chances of finding something you really like. But, as others have mentioned, Viking seems willing to work with you, if you really dislike an included wine, to find a suitable replacement. What we observed is that they cycle through various included wines - so it isn't like they serve the exact same red, white, and rose' every meal.
So back to the OP's question - Are the "premium" wines at Chef's Table worth the extra $25/person? I think if you view it as getting the optimal pairing for the menu, then it is. If that isn't important to you, then probably not. Either way, it should be a fun experience! I hope you enjoy whichever menu(s) you select as well as whichever wine pairing!