My old Sky+ box was replaced because the card reader did not work, and it will not record or allow you to delay viewing, however it still spins up the hard drive from time to time and even on stand by still powers the LNB so uses at least 8W which is what the LNB requires.
The free to air boxes however have no problem recording the free programs. But with some the format is not compatible with other computers, so the recorded program can only be played back with the box used to record it.
Not all are set that way, my mothers box can record to a FAT32 formatted stick and I can watch on any TV.
But what the box will do seems to be pot luck, my Blu ray player will allow me to watch all sorts from the internet, but mother free to air box which we though would do the same seems to need some special codes.
The old Philips DVD recorder I had worked A1, it would record 8 hours of TV and you could either go back and see what you had missed, or convert that 8 hours into a recording which you could then select which bits to keep. Then transfer onto a DVD to watch years latter.
However I found the DVD's did not all want to play on the blu ray and some did odd things like a loop which played just part of the DVD over and over again when played with another reader.
Even using the PC to record has not worked that well, with a slightly distorted image.
I have to give Sky their due, recording programs does not only record the program but also all the data with it, so you can still view the program details after recording. There seems to be no loss of quality and I often record on the Sky box then transfer to PC.