I went to the first year, but just for the sunday (mostly to see Nine Inch Nails' last uk gig, which both sucked balls, and turned out not to be their last uk gig, so hurrah for that).
It was really bloomin good... The bill did feel a wee bit thin, we only went the one day as it felt like 1 day's worth of festival pushed around 2 days, just like Download etc always end up. But the site was excellent, wee bit flat but otherwise bang on. Great atmosphere, I ended up gutted we weren't camping. Felt a wee bit middleaged possibly, but not badly so- didn't have that bullshit atmosphere of forced fun that some do.
Oh aye, and they had the total genius idea of having different stages close at different times, so while everyone else was leaving Metallica, we went off and watched Hundred Reasons- meant a bigger audience for the smaller stages, and less pressure on the exits etc. All festivals should do that...
Only criticism was that the shuttle buses from the town were a disaster... we queued for about 4 hours and missed SAXON!11!oNE. Then it turned out that despite everything they said on the website, it would have been an easy walk to the site anyway. So both incompetent, and unneccesary. But that's fairly trivial on the grand scheme.
So yeah. Ace. Might be going back this year, I hear Metallica are going to do Lulu in its entirety