I don't use this software often as I do not build many new sites, but when I do I like to write the first 5 or so articles and this is when I make use of IAW.
What it does for me is it helps me research my topic by searching multiple places online for each article and put this information in one place. I then take the snippets I find and copy and paste them into the best spinner where I take the information and rewrite everything in my own words. So its kind of like building an essay for me, layout my article with headings sub headings, intro and conclusions etc, and then research each piece and then build my articles.
I can not put an exact number on the amount of hours this software saves me in my research but I know it is a big number.
Sometimes the software brings back crap as well, but like any software that automates some things you need to learn the ins and outs of it before making use of it.