I have met Gavin and he was amazing. He's not only a very nice man but also very respectful and very caring of U2 fans and his own fans.
For those of you who think that he is only famous for being Bono's friend ... you're wrong. The man is considered one of the most talented artists in Ireland. He has a great voice, and he is well known in the business for producing great soundtracks and many talented and recognised artists go to Dublin to record their albums just to work with him.
Besides, to understand how much he influences U2, you need to see Gavin performing to realise that Bono takes 90% of his moves from Gavin.
And one more thing, the reason why U2 hired him as a consultant is because Gavin is very professional and the band knows that Gavin Friday speaks his mind and he will provide the right feedback to them. Gavin will say what he thinks whether U2 likes it or not, the band trusts him and respects his opinions and ideas.
Have a nice day,
Blue.