For one thing, is Kelley's "reductive focus" really the same as Nelson's "inviddying of scene-images"? Maybe I need a translation table! (Update: In both cases the idea refers to the kind of seeing we do when we see that a circular coin "looks elliptical" at an angle.)
Nelson's book is funnier, and easier to read for most people. Kelley's book is addressed to those trained in contemporary philosophy, and is more academic in style.
Both authors are out to rescue the idea that our senses are really in touch with reality. Of course, most people do think this, but many philosophers have thought otherwise!
Quee Nelson has a lot of examples of this skeptical philosophical tradition in her book's appendix. I like this one:
A. J. Ayer: “From our resources of sense-data, we ‘construct’ the world of material things.”I often get tired constructing the world of matter.
Ideas are so light. You can toss them around with mere chatter.
Material things have such weight. They're so hard to build with.
But nice fluffy sense-data - that is something I'm skilled with.