The Roku interface allows incredibly easy access to cable, streaming apps, and/or other devices such as DVD players or gaming systems, without having to switch inputs or other things guests may find confusing.However, I also agree with @Nancy Bachety that it's about knowing your guests.  

One time I made an inquiry as to why, zillow replied that they have humans doing checks on some listings to ensure they are not bogus, so there is a manual process somewhere in their data mining layer.Zillow has a better interface and the ability to see a map and visualize recent listings and close by sold listing is very nice.To me zillow.com has the better interface.Realtor.com has more updated information.One way I use zillow, is when I get an alert on a new listing from somewhere not zillow, I go to zillow, and most of the time, I can still see the pictures of the previous listing of that property, and that's very useful LOL.

The interface is just not as easy, you have to click too many times to achieve something simple.

They have a really good system, though the interface needs to be updated (and I understand that’s coming).

Hopefully your property condition reports are up to date, if not, schedule an inspection now and document the current condition of the property.Also, if you feel uncomfortable approaching the tenants and perhaps are in fear of them, then hire someone to do the interface for you.

I use a shlage with an apple tv as the interface through wifi.

Podio is very customizable so it serves as the "central hub" or "interface" and creates the relationships between items.

Off the bat, it appears to be phenomenal (capabilities, reasonable monthly costs, interface, provided information, etc).

DVR is still superior in my mind, most of the cloud ones still aren't quite...there yet...if you're looking for constant and consistent recording of everything that happens.If, however, you just want to open an app and view what's going on with limited ability to go back in time and are willing to put up with some gaps in recording, probably ARLO or ARLO PRO are the best at the moment for easy setup and interfaces. 

You could create a nice base product and work as a consultant to ensure it interfaces well with the customers areas of interest.