I barely know where to start... as a long time brooks revel wearer (I've owned revel 1, 2 &3's) I am well versed in this particular style of shoe. i started wearing it 3 years ago as it is the only athletic shoes that helped my plantar fasciitis. This re-design for revel 4 is complete trash. They have down graded the fabric of the shoe to a very thin, flimsy, cheap plastic feeling fabric. Though, my biggest complaint is that the achilles notch (the back part above your heel) has no cushion or padding now, they also raised it so it sits higher on your ankle. These changes have caused two results, the shoe rubs against your heel as you walk and it doesn't secure the shoe well onto your heel which causes friction as it rubs. This leads to blisters on your heel. Due to these awful changes they have made with these redesigns the shoe now fits a half size too big as well because they removed what helps the shoe fit snugly to your foot (thicker quality fabric as well as the cushioned achilles notch).
Furthermore, when ordering I had purchased both the denim blue and the black/coral pair. I was only sent the black pair but charged for both. After having to file a complaint through amazon the company has agreed to refund me for the missing pair.
TLDR: Don't waste your money or your feet will regret it.