Allardyce's men go into the international break seventh in the Premier League following wins over Liverpool and QPR in recent weeks.
Diafra Sakho was on target in Sunday's win over Harry Redknapp's side as his strong start to life at Upton Park continued but Allardyce has also been impressed by the likes of Mauro Zarate, Cheikhou Kouyate, Enner Valencia, Aaron Cresswell and Alex Song.
However, the West Ham boss acknowledged a degree of surprise about just how well some of his new arrivals have adapted.
"If I'm honest they've settled in quicker than I expected," he told the club's official website.
"Kouyate made a fantastic impact before he got injured, obviously Valencia and Sakho have been brilliant as well. Mauro has found it a little bit more difficult but overall has done very well.
"Aaron Cresswell looks like he's played in the Premier League all his career. We all know about Alex Song, he's not even fit yet - when he is, we'll see even more of him.
"Our strength in depth was tested [on Sunday] as we had seven players out injured but I thought we coped magnificently."
