It always raises a smile when there are objections re GSTQ as anachronistic, but then Jerusalem or LOHAG get advanced as alternatives
LOHAG is easily the best tune for this sort of thing, and in the land of the greatest ever lyricists it shouldn't be beyond the wit of UK man (or indeed woman) to come up with a 21c set of words for it, and that would be my vote.
Jerusalem? Good hymn, as far as hymns go, also a decent sing-song, but apart from "England's green and pleasant land", the words really are a crock of utter shyite.
Land Of Hope And Glory 2012 anyone?