Thanks for the overview. It's always useful to hear real user experiences rather than just reading the marketing material. A clean interface and effective junk file removal are definitely important if you're looking for this kind of software.
There are quite a few Thunderbird users around, so you've definitely come to the right place. It's a solid email client, but the exact setup or troubleshooting steps often depend on the email provider and what issue you're running into.
If you describe the problem you're having, I'm sure...
I'd say the internet connection is still the biggest factor. Even the best TV or PC can't make up for a slow or unstable connection. After that, the router becomes important, especially if you're streaming over Wi-Fi or have multiple devices using the network at the same time.
The playback...