Yes, I have seen them all but they seem to be too new and too buggy to actually purchase yet, many are doing pre-order of their doorbell, they should have seen this coming in 2013 when the ring was on TV and start to realize people wanted this, not sure how they missed this so badly but they did.
At the end, there is only a small group of people that want to do this setup and take the time to download and setup Bi.
Hi TL1096r,
Hikvision and Dahua have had a number of door intercom camera systems, as have others FAR longer than the history of Ring.
Hikvision and Dahua business models have not been to sell directly to the end user.
Thus it really is not truly a situation: "..not sure how they missed this so badly but they did."
Remember their ( Hikvision and Dahua ) business model is not a cloud service provider - which is what Ring and Nest really are.
The business model of Ring and Nest are completely depending on you to pay significant money to purchase the camera - then after you've paid for that, to charge you regular service charges.
For me personally, I do not like the idea of leasing a car - on the long term it is more cost effective for me to actually own my car.
Same I feel about security cameras - I'd rather own it, than lease it.
Yes, a large number of consumers are happy today to jump on the easier to setup solutions which lock down the products they "buy" and force them into service contracts ( recurring revenue for the companies selling ) to get full functionality. Unfortunately many people who do not know better will be paying significantly more in the end when they could have installed a better system from the start.