Mike,
Concur with almost all you have said. Especially about the crappy Spectrum DVRs. One of my biggest gripes about the DVRs is that they are separate and don't talk to each other. Almost every one of the seven places I've lived over the last 15 years have a main DVR in the living room and then a "slave" small box in the bedroom that will play anything off of the DVR. That way you don't have to have separate recordings in the bedroom and living room. There is only one DVR and the slave units act as an extension of the DVR. Spectrum doesn't offer this feature even for their market rate plans that non-SCPD customers have.
Currently, since the Spectrum DVRs are not great, I have a TiVo DVR. While the TiVo experience is the best in the DVR industry, I would not recommend them for SCPD residents as they require a CableCard and Spectrum no longer supports them and you need one from your cable provider to make a TiVo operate with cable.
If/when my Spectrum CableCard gives up the ghost, I will have two external options as I don't believe the Spectrum DVR is an option. My first choice will be DirecTV, as they have the second best DVR in the industry and is usually exceptional service. I've had DirecTV at six different locations across the US. Weather has hardly been a factor anywhere, and you can customize your service to match your desires. Like I've previously said, they have a slave unit for the bedrooms. Downsiides are that you have to have a dish on your property and that it can be expensive. But if you want some of the best tv service, you'll get it with DirecTV.
My next option is YouTubeTV. Not YouTube, but the full tv service that you run via an app on your tv or a set top box like those you've mentioned. It sounds similar to the Spectrum online service you described above. Many similar features. I just really like it because it mimics a DVR better than the Spectrum service.
I also have to agree with you that the AppleTV 4K set top box is the best in the industry. I've had AppleTV units since the first one they released and haven't found anything better.
I think you covered the audio side of things exceptionally well. Thanks for the write up.
Joe