u/This-Aerie-6929

So I have a mini JCW 2015 , before buying the car I seen so many reviews about how good the brakes are , well I don't feel like mine are that good , the brambo discs and pads are fine . Brake fluid recently been changed , they seem to bite straight away but then when I'm really hard on them they don't seem to brake that well , it's like oh I'm gonna stop these are really good , 2 seconds later , it's like I hope I stop in time lol . I have an auto and when I put it in reverse, they squeal now and again , yet I've had them checked my a mini specialist and they say they don't need changing . Any help would be great