Alex McLeish brought in seven new faces over the summer, notably three on deadline day in Alexander Hleb, Martin Jiranek and Jean Beausejour.
The Blues have responded with an unbeaten start to their Premier League campaign with a win and three draws, giving them a healthy fifth place in the table at this early stage.
"At the end of last season we lost quite a few players and we knew coming back this season we needed strengthening," Dann told City's official website.
"We were hoping the manager could get as much money as possible to bring in as much quality as possible and he's finally done that now to the extent that he could.
"I think when any new player comes into a club it keeps you on your toes and brings out the best in you as a player and as a person. I think all the lads will be having a little look over their shoulder and thinking 'hang on a minute he's not having my place' and step up to the plate.