At launch, the beta testing will only be available to Sling TV subscribers who use a Roku device. We don’t yet know whether Apple TV subscribers will also be allowed to join the beta before its completion.
You can apply for a beta invite at this link.
During the beta, Sling TV test accounts will support up to 100 hours of recording with no expiration. Once you exceed that limit, Sling will automatically delete the oldest recordings as needed.
Sling said that it’s working on more DVR options, including storage upgrades, but cautioned that for now recording won’t be available on all channels. There’s no indication of when the technology might come to other platforms like the Apple TV.
PlayStation Vue offers DVR functions with a 28-day limit on all recordings.