No there is no DYS vs Scripts from my point of view:
It should not be seen as "versus " :
See as opposite, antagonist options will create dramatic self imposed limitations
"Do by yourself" could become a nightmare when force to do manually endless series of boring, repetitive gestures, poisoning the joy of the creative flow
But know HOW a script plugin works,( i don't mean understand its code but just know what steps automatize , what does to the image ) give a more natural, relaxed yet complete control of the results,
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A quick example clear the concept , the old "Layer effects " script and its "Drop Shadow"
In this case to got what the script does it is only needed to check "preserve layers " before run it and to see the new layers
I am not too happy of that drop shadow script
but once i saw what the script does and how (just looking at the new layers it create, are self explicative ) i could see how improve (i duplicate the new layers, apply progressive amount of gaussian blur on the "shadow" , and re tune layers opacity )
As only DIYS I would never find the patience to do all manually,:gaah
as only script the default sucks
and if you don't know the manual correspondent would be much harder learn how to use it at best
(FOR SCRIPT FU, for Plugin the preview may help to explore something more adapt then the default )...