I saw three shows in Norway in the 90s, and two on the Invaders cycle. The Invaders European club tour gig at Sentrum Scene, Oslo, was by far the best one I've seen, but the one at Oslo Spectrum (also the Invaders cycle) was by far the least favorable. Of the ones in the 90s, the gig at Kalvøya, on the day before the release of FOTL, was the best one, by far the best out-doors gig I've ever seen, maybe with exception of Pink Floyd (Valle Hovin -94) and Slipknot (Download -09).
I might have such fond memories of the Kalvøya gig since that was the first big festival I went to, and I might not like the Spectrum -09 one so much ´cause of the free age limit (The bull that forgot he was once a little calf?) %) And I've always loved indoors (pref more intimite) concerts, regardless of genre.
So to put it short: outdoors and/or stadium gigs: 90s best, club gigs, present best. (I didn't see the Milton Keynes gig live, but I've seen the DVD tons of times. Seems like a candidate to best gig ever, tho)
So to put it even shorter: very hard to tell.