Foster made a £6million move from Manchester United during the summer after a lack of first-team opportunities.
He had a hard act to follow after the outstanding campaign enjoyed by Joe Hart while on loan from Manchester City laid the foundations for him to become the England number one.
But Foster has been back to his best for Alex McLeish's side and kept another clean sheet during yesterday's goalless draw at Aston Villa.
And McLeish has claimed Foster made an even better start to his time at St Andrew's than Hart, who was guilty of early-season errors and uncertainty.
Foster said: "It is nice to hear things like that. Joe has done really well this season and last season as well.
"I think the start of last season was a bedding-in period for Joe. He had a few seasons when he hadn't been playing regular football and I know how that is. It is not nice.
"When you can finally settle into a team and know you are playing first-team football and are an important part of the team, it is a good feeling.
"It is something I and him similarly get a buzz from.
"People say I look full of confidence but it really is just from playing first-team football, knowing you are needed and wanted.
"It's a feeling I've not really had for a good few years and I'm loving every minute of it as well."
Foster is also quick to recognise the influence of Birmingham goalkeeping coach Dave Watson, the former England Under-21 player.
He said: "Dave has been fantastic. I met Dave just before I signed. I'd heard a lot about him which was so positive.
"Now I'm here he is a great guy to work with. He is a bit busy at times but he is a top man.
"He is one of those who will listen to you but you know he is always going to give you plenty (of advice) back as well."
Foster's outstanding form has also provided a personal bonus by helping the success of his "dream team".
He joked: "It is nice to have had two successive clean sheets and good for my dream team, because I am the goalie in my team.
"In my mini league I'm on fire. I'm top at the minute. I'll have to wait to the update to see where I am."
Meanwhile, Villa defender Luke Young praised the derby performance of rookie defender Ciaran Clark, who was employed in an unaccustomed holding midfield role by manager Gerard Houllier.
Young said: "The goals are not coming for us at the minute but I think a big plus was Ciaran Clark's performance in the centre of midfield.
"The manager has spotted something there that no-one else saw and he was brilliant. It looks like a role he could fill for us.
"We had a few jokes that when Birmingham got our team sheet that they would think we were probably going to play three at the back or something like that.
"I think we all believe Ciaran is a good ball player and he showed that and played really well."
Young is pleased to be back playing ahead of schedule after missing three matches with a hamstring problem.
He said: "It was just nice to get back out there and get a game under my belt because I've had a frustrating couple of weeks.
"The plus point was that I managed to get back a week before I probably felt I would. I pushed on the last couple of days and managed to start."