As a moderately experienced K programmer, I find K easy enough to "scan". Common idioms immediately stand out as recognizable "words" that are suggestive of what a routine does before you fully parse it:

@& (filtering)

@< or @> (sorting)

@\: (folding)

,/ (flattening)

+\ (a running total)

etc.

It's also easy to notice, e.g. in K3, a reserved name like "_f" and immediately know you're looking at a recursive procedure.