I'm fond of CTB because... we're already set up for it
CTB basically works like this:
When plotting, the CTB file is read, and every object is plotted to a lineweight that associates it's color to a thickness in the table. For 'standards' one would logically set their objects to ByLayer and thus the color would be whatever you set the color to in the layer manager. This allows you to have color overrides, so that you can change the color of the individual object if you want it to be thicker/thinner than standard for some reason. These individual color overrides take precedence over the CTB. This has a drawback though. If you override a color, and that drawing is xref'd into another drawing, you cannot set that object to shade by turning the xref'd layer to a shaded color... because it no longer cares what the layer color is; it has been overridden. However, I don't know that STB would solve this...
CTB has a benefit (subjective benefit) of being able to quickly know how something will plot, by seeing what color it is. STB has the same, if'n you just check what layer it's on, afaik... but I find the color correspondence quite nice. I'm just comfortable with it. My brain can quickly see what is on the screen, and come up with how it will plot, without having to plot-preview or check layers or what not. If all objects are set ByLayer (as they should be, subjectively) then you can also quickly assess if there are objects on the wrong layer.
I do not think that setting each individual object's plot properties (color, thickness) per object would be feasible at all if you use xref's and ever want something to show differently on one sheet, as opposed to another that it is xref'd into... because then you wouldn't be able to control it separately.
After reading many discussions on the site about CTBs, STBs... my conclusion was that they do pretty much the same thing with very little different... and the differences that exist are so minute compared to the overall picture and function that it seems to me that either is equally functional and beneficial... it's just whichever suits your brain, I guess.