When I say it acts like a suction cup, there is a clearly audible noise when I lift my foot (yes, audible to bystanders) as if you’re pulling up a suction cup. When walking on flat smooth surfaces (garage floor, tile, hardwood floors, etc.), that pocket acts as a suction cup, likely because of the flexibility of that window. I also scrolled through all of the reviews to see if this has been mentioned and am a little surprised I didn’t see it, but there’s a design issue with the triangle-shaped pocket on the bottom of the shoe with the transparent window to the transparent foam. I’d say the increased width and traction are an upgrade, but as a non-runner those aren’t as important to be as cushion.
I would agree that the carbon plate is not as strong as the ZF4 - those felt like they were literally adding energy to my stride while these lack that pop. That said, these feel like a noticeable downgrade from the ZF4. I’ll say up front that I buy running shoes exclusively as daily use shoes for walking etc.
