Thanks for the replys and pictures, really useful.
I ran Eibach springs on my old
330D E90 and was pleased with them.
I think i'll go down the
ACS route this time round for the reasons people have mentioned. Plus the Eibach springs looks like they have a slight difference between front and rear lowering on an F36 in some pictures and forum posts.
Will post some picture on here and
build thread once I get round to sorting out. Quite a big arch gap at the moment so keen to get some fitted sooner rather than later!