I brought this way back ago. Neville and Giggs aren't suited to coach the team.
Neville is an ex United squad player, he moved to Everton to get first team football (because he's not good enough to do that with us, and its not his fault we have better player in his position), he has been trained by midtable coaches for the past few years, playing midtable football with midtable resources, there is nothing that suggest he will do a better job than any of our first eleven.
Giggs are just there for the influence, what he possess is sublime technique and longetivity, something you can't simply pass along to the rest of the team. You can make a case for Ole because he is tactically astute even in his playing year, judging by his reading of the game.
They could have been brilliant given the time and all that, but at the moment, it is hard to portray the players taking them seriously. Giggs is the player they respect, but technical and coaching wise, he's no better than the rest of the squad. What Giggs get everyone get at one point of time, there's nothing that Giggs knows and the rest don't know.
With Rene, at least he's a professional coach, and not an ex footballer, even if he's young and hasn't won anything, he has done his homework as professional coach for years. This alone will make him seen in a different way.
And I suspect, turn it the other way around. If Ole was given Everton to manage 10 years ago, I'm sure he won't be that far off with what Moyes has achieved.