If I understand Yale correctly, when I order from C4 it has a ZigBee module installed that only works with C4. It appears there is an option to swap out for a $129 network module in the Yale lock that works in the August app that then connects with other "controllers" through the cloud. But with the C4 version it will only work in the C4 environment. Do I understand this correctly?

There are much better reviews on Yale over Kwikset using Amazon as a proxy.

I like the 9v battery trick Yale offers and the ability to get rid of keys (but 3P notes a cool feature with Kwikset if trying to match keys to a home).