TLDR: Great product, may not work like you expect
I was under pressure to get a mesh network in place at our small business (because boss read about it in business journal and wanted to know why we didn't have it already). On watch lists all over for this item to become available, but every time I received notification, was sold out.
The hardware itself is extremely well made and wireless performance is on par with our best single access point routers. Put this in place in mesh mode thinking that it would work as an all-encompassing wireless network. Access speeds extremely fast, coverage great!
Went home, and the next morning my entire network was in an uproar. This product is designed to REPLACE your networking equipment. As such, it hijacked DHCP and put everyone on a different network than our wired network. Everyone could access the internet quite quickly, but nothing inside on our wired network!
Corrected this by putting this in "Bridged" mode. Doing so, however, makes them function like single access points - no mesh! I was able to get mesh-like by using the same SSID, this this is a really bad work-around and there is no reason you couldn't do both. Google reps have acknowledged this and indicate that maybe it will be fixed in a future software update.
This is definitely a consumer item, and I think Google should have made this much clearer! Please note this affects not only small businesses, but also consumers who can't remove their existing equipment from their networks (such as combined TV/Internet services requiring set-top boxes). Due diligence is necessary to make sure this product will work with your setup.