This has been very interesting to read. I am considering upgrading my DS8 as well. One thought that hasn't been mentioned about TS meals is that the child's meal is generally prepared differently, without glazes, sauces, spices, and flavor. My DS really appreciates flavorful food and I have heard more than once about bland children's pasta and dry grilled chicken.
I understand that many people do buffets and thus the TS side of the equation doesn't compute, but if you have an adult that is mostly a salad eater and a child that can easily eat an adult portion of filet or salmon, then upgrading may make sense.
For our situation, I think upgrading the CS meals makes good sense too. Everyone is right, there is so much food to share. So why not get another shareworthy CS? For my family of 3, that would equate to another "shared meal" for every two days, which for ease of planning could be really nice on vacation. JMHO.