That depends on a lot of stuff.
I am unclear why you believe adding a calculation field (or several) to the table itself is best for presentation, but, in those cases, it might be worth it. I tend to avoid adding data fields of all kinds -- but especially unstored calcs -- to a table unless they are necessary.
I also have finer control over the appearance of merged text on a layout than with calc fields. The various pieces of merged text in a block can be formatted separately if desired, but creating a formatted result in a calc can be a ton of work, if it works at all.
Looking down the road, I would not want to build a complex solution which relied on merging via calc fields, and then have to go in a modify "some" of the places it appears, while the users may prefer some places not to be changed. Text blocks allow that at the layout level. On the other hand, if you are confident that changes will be an all-or-nothing modification to all instances, then modifying a single calc result would be faster for updating a bunch of layouts.