When I first wore these shoes at work, great bounce and easy walking.. some numbness after 11 hours, so I changed back into my other work shoes.  Second time I wore them, they were fine.
You can feel where they are exercising your legs.  I like them a lot!  Funny story, I went for a 2 mile hike, pretty vertical climb up & down, I wasn't used to that at all.  When I got back to work 2 days later, my calves were screaming, so I put on my Shape ups, and felt a whole lot better as the night went on.