Pros
Many potential employers have remarked when they see Wayfair on my resume that they know I am dependable and hard-working. They have also said "Wayfair - what a meat grinder". Many of the people I worked with were some of the smartest and most talented people I have ever met and I learned a lot in my time there.
Cons
The 6 month evaluation cycles produce anxiety across the entire organization, and things may have changed but in my time there they were seeking to let go of what they considered the 'bottom' 20% every 6 months which meant that we were constantly training people who really wouldn't even be allowed to make any sort of impact on the team. I was there when the first layoffs happened and when I asked if that meant we would not bring in a fresh wave of direct from college recruits I was told no - they would still all get hired. To me this shows that Wayfair understands that they are constantly hiring so they can fire and are not trying to stabilize their organization. Just my two cents. If you do not have an aggressive personality or ability to stand up for yourself and your team, you will simply get eaten alive by this culture.