I am so miffed by the demonstration put out by the company in the video (click the title of this post to see the ad) that I almost wish I hadn't. Notice how she purposely does not even ink up the wooden stamp? Notice how she purposely gets ink all over the edges of the acrylic block and then actively rocks it on the paper to cause smearing?
Wooden blocks and acrylic blocks generally work fine with most stamps if you pay attention. I ordered the Rock a Blocks last week for a few of my larger acrylic stamps and particularly for stamping when I stamp lots of cards with the same image (Christmas cards, cards for my students, etc.) because you can work faster without messing up.
I hate this sort of advertising which implies we are all too stupid to make sense of an honest demonstration. It really bugs me!