I think a lot of people undermine Giles' contribution to England winning the Ashes in 2005, yeah he didn't ran through the Aussie batting line-up or anything, but he did carry out the job that was given to him very nicely.
His captain asked him to bowl a negative line, not give away too many runs, and he pretty much did that, and also took a few top-order wickets while doing so.
As for whether Hauritz should play at Cardiff or not, I am pretty clear about one thing, that Hauritz shouldn't have been in this Ashes squad in the first place, but since he's there now, and that too as the only spinner in the team, he should play at Cardiff, it would be pretty diabolical if they repeat the same mistake here, that they made during the Indian tour.