Not sure Billings has ever let England down when he has played agree about the others
Billings hasn't exactly let England down, but I do think that he hasn't shown the same quality at the higher level yet.
Out of Denly, Dawson, Vince and Billings, I think that Billings may be the more exiting player if he can genuinely step up. Although with Banton, Salt and Hain you would surely have enough potential "young blood" fire power.
It is rather nice to have the luxury of so many young potential players around!! In the "olden" days, the English teams mostly picked themselves and were pretty straight forward, with not too much discussion needed.
But to have so many players in the running and so many future hopefuls is kinda nice!