Frankly I think they did well. All of them but Dimitrov and Dolgoplov beated the guy they ought to beat and lost against players against whom it was expected for them to loose.
Nishikori lost to Ferrer, Raonis to Federer in the 4th round.
Janowicz to Almagro, Berankis to Murray, Tomic to Federer in the 3th round.
Goffin lost in 5 set to Verdasco.
Dolgopolov should have beaten Monfils, but it is no shame to lose against him, especially when he serve so well.
Only Dimitrov disappointed me.