I use mine for permanent storage, I have things on mine that are no longer available on demand from sky
You know what the shocking thing is... I did this for one other main reason. It's shocking to see recordings on my box as far back as 2013 and seeing how much Sky has butchered video and sound quality over the years. The files are massive on some of my boxes compared to what is being recorded today. Yet the old recordings are pretty close to Blu-Ray quality. Not quite but close.
Some films like Lord of the Rings back then would be over 20GB for each part.
Where now, it's horribly soft and bordering out of focus with so much compression they've been applying. Plus most films now recorded are at most 2.6GB. As some older films from 2013/14 ranged 8 - 9.xxGB. But the bigger file sizes are worth the image quality.
Men at Work 1990 recorded on MGM back in 2013, 107 minutes 9.06GB. Yet the picture quality and sound is glorious. Today? Nope, it's quite abysmal the picture quality on Sky Movies broadcast for the majority of films.
You can really see how much Sky has butchered the image quality when the Plasma shows up all the banding and macro blocking in the shadows for quite dark films. Even Standard Definition DVDs look nothing like this. A lot of films on Sky with so much compression that they've added you're losing the film grain from some films.
People on the AV Forums has been talking about this even with Sky Q over the years as well.