On the plus side, Silverwood is an English coach, has a good relationship with the players and has had success as bowling coach and at county level with Essex.
On the other hand, it sounds almost as if he was 3rd choice after Alec Stewart withdrew his application and Gary Kirsten got cold feet over the travel commitments (and also apparently gave a boring presentation at interview.)
Personally, I would have preferred someone from outside the current set up as I think Root & co are complacent and get too defensive over justified criticism of our Test match batting.