which came out a shockingly long time after airing on TV
For the first few seasons, the DVDs didn't arrive until February (so almost a year after transmission, given that the first show in a season used to be broadcast in April). Thankfully, we've had the last few of them in time for Christmas, so I watched the first three episodes on Christmas Day, and the last three yesterday.
Now I knew what was going to happen before I loaded the first disc -- I thought it pointless not to follow what was happening (so read the Grauniad's weekly episode summaries, as I've done every season), as I prefer to find** out things in the correct order rather than randomly and out of context -- but still fully enjoyed this season.
But perhaps that "but" should be an "and": knowing what was coming allowed me to recognise lots (perhaps even all?) of the signposts pointing to what was going to happen. Because of this, I felt in no way cheated... although, of course, I'd have preferred the season to have been longer because, well, I enjoyed watching it and would have gladly watched more if they'd made more.
** - I saw this as no more than an extension of having read the books before watching the show: knowing what was in the books (and in far, far greater detail than could be in an article per episode in a newspaper) didn't spoil my enjoyment at all, even when the show was being more or less faithful to the source material.