Mackie, a £1million-plus arrival from Sky Bet Championship rivals QPR this summer, scored his first goal for the club against Bolton on Saturday.
It was the forward's fourth appearance this season, and third start, and Mackie's work rate, energy and determination have caught the eye in all of his outings so far.
Davies has predicted that the 27-year-old will work his way into the hearts of Forest fans.
"Mackie is what he is and the fans take to him because he gives everything he has got," said Davies.
"His work-rate is second to none. His attitude is second to none. He is a great lad in the dressing room.
"I have to say that we have a fantastic spirit, even with the new players who came in.
"It is nice to have players like Mackie. I believe he will be a fantastic addition, along with one or two other guys, once we gel them together."