Just wanted to give a quick feedback since I see lot of folks discussing the same topic here.
I installed Akebono ceramic pads on my 328i (both front and rear) along with Zimmermann zinc coated rotor on the front. I reused the existing rear oem rotor since it was fairly clean and no lip. I also did Brake flush (within 200 miles) after the brake pad/rotor replacement.
The first few 100 miles I barely had any feedback at all on the brake pedal. And the pedal travel was longer than normal too. After about 600 miles, it started getting slightly better but still the pedal travel was longer to even feel a slowdown.
I now have 1100 miles on these setup and its getting AMAZING. Some of you may say I just got used to this setup but trust me, that is not the case. Although the initial brake bite is still not the same as OEM, the initial tap on the brake seem to work pretty well again. Its unbelievable it took 1000 miles for these pads and I was starting to worry I made the wrong choice. But now that fear is out. These are definitely good and I like that there is barely any brake dust if any.
I have seen many people say that it took their car almost 1000 miles before the pads were behaving like OEM. So it seems like a common behavior for Akebono pads.
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Update (03/20/2018): After putting almost 35K miles on these pads, they barely show any sign of wearing down. The pads and rotors both look fairly new. Little to no dust at all at any given time. BUT........ here is the problem. I have been parking my bmw out lately as I acquired another car. And during winter, the pads took a while to warmup. I almost thought I had glazed rotor/pads and even had it inspected. But as the temperatures are going up again now, I see that the brakes are working fine again. So, I have been having mixed feeling about this. I miss having the initial bite of the OEM pads.