After a week of letting my cats use the litter (and they did indeed decide it was acceptable), here's what I noted.
Will I try it again? Most likely. I'd really like to get a big bag of their multi-cat formula and see how long it actually lasts. I couldn't give that part a fair review. If/when I do, I'll try to update things here to let you know how it turned out.
An important side note as was given me from World's Best:
"World’s Best Cat Litter™ has launched a new charity that will donate much-needed cat litter to animal shelters and rescue organizations! The World’s Best Cat Litter™ Charity enables our fans on Facebook to donate litter and vote on 3 great organizations who will receive all of the litter at the end of 45 days!"
You can go to their web site and find their links to facebook (where the voting is being held) as well as on Twitter.
(I was given a sample of this litter to try and give my honest opinion of. I was not in any way compensated or otherwise influenced.)