I recently purchased an e61 and was shocked how bad the brakes feel compared to my e60. They overheat and start shaking the car after one hard brake and the pedal doesn’t feel as stiff as in the e60. I will be changing the brake fluid regardless but can’t decide between replacing the pads and rotors currently on the car or upgrading everything to m5 brakes. I was thinking of getting the m5 calipers and rear hubs for the conversion off rock auto since they are so cheap and then getting hawk hps pads and Zimmerman rotors from FCP Euro. I wasn’t sure if the calipers and hubs from Rock Auto are nice enough to be considered an upgrade or if I should just get the the normal e61 size hawk pads and Zimmerman rotors with the calipers I currently have. I already have 19 inch wheels on the car so am not worried about clearance. I would also do stainless steel brake hoses if I went with the m5 brakes. I was going to go with Centric/C-TEK for all the rock auto parts. I live somewhere where they use a lot of salt on the roads in winter so the parts need to be able to hold up but I would at least be painting the calipers if I got them.