Note that the difference between the Home tab and the Remote tab on Nucleus has nothing to do with physical location. You can set up your parents' device in their home with your account and you'll still be able to instantly connect to it from any of your Nucleus devices.
When you make a call, the clarity of the video and sound will largely depend on the speed and stability of your internet connection. Even at its best, don't expect crystal-clear HD. The connection is serviceable. You'll be able to see and hear what's going on.
Weirdly, during testing, when I called a room with no one in it, I'd occasionally hear squeaking feedback for the first couple of seconds of the call. During one test, that squeaking feedback grew in intensity to the point that I had to end the call. I never noticed that problem while chatting with an actual person.
A smarter intercom
Not only will the Nucleus let you check on your family, it doubles as an Alexa device. Link your Amazon account in settings, and you'll be able to give voice commands to Amazon's digital assistant without pressing any buttons. Like Amazon's always-listening speaker the Amazon Echo, the Nucleus responds to your voice commands and can hear you even from across the room.
Say the wake word "Alexa" and you can set a timer, check the weather, make a list, control your smart home and play music. Alexa can do a lot and a Nucleus gives you access to most of those talents.
Amazon's speakers stream music from a number of sources, including Spotify and Pandora. Because of licensing issues, the Nucleus can't stream from third-party sources like Spotify, but it can stream music from Amazon Prime and the rest of Amazon's linked streaming services.
Set up a Nucleus with Amazon, and you'll even see it in your Alexa app. Be aware that the Nucleus doesn't work with Amazon's ESP feature. If you have multiple Echos, ESP prevents more than one from responding if both units hear a command. Because the Nucleus doesn't have this, you'll want to be careful about putting it too close to an Echo to avoid overlapping responses.
If you activate Alexa's Nucleus skill (Amazon's term for Alexa's optional functions) with your voice or via the Alexa app, you can make a partially hands-free Nucleus call. You need to use the invocation words "tell Nucleus." For example, you'd give the command, "Alexa, tell Nucleus to call the office" instead of just saying "Alexa, call the office." This way you can begin a chat with a remote family member without either of you touching the device.
You can't hang up with a voice command, so it isn't actually hands-free. And you can only give the command to a Nucleus directly -- an Echo won't start a call for a Nucleus. Nevertheless, the integration is thoughtfully done and works well, greatly expanding the Nucleus' capabilities not only as an intercom, but as a personal assistant and smart home controller.
I wouldn't recommend a Nucleus over a $180 Echo and especially not over a $50 Echo Dot. The microphones on the Echo devices are more responsive -- those on the Nucleus aren't bad, but they won't hear you over any background noise. The Echo also has better sound quality for music. The Nucleus is roughly on par with the Dot in sound quality, but you can plug the Dot into your own speakers for much better sound.
Plus, the Nucleus doesn't add much besides its intercom feature to the experience of Alexa. If you search with Alexa, it won't display results on the screen.
The Nucleus also works with the Ring Video Doorbell, though the integration is still in beta. When I tested it, it worked fine. If someone presses the button on the Wi-Fi-connected doorbell, the Nucleus rings, and you can have a video chat with your delivery guy from your Nucleus intercom.
Don't buy the $250 Nucleus Anywhere Intercom just for Alexa, for the Ring or for the touchscreen. Add those features to its primary function of making video calls and you still have a device that's much less useful than a smartphone.
However, if you have family members you want to check up on, especially if that auto-answer feature would come in handy, then the Nucleus makes more sense, and those extra integrations put it over the top as a solid purchase.