After reading mixed views on these I bought some anyway and after experienceing none of the noises some people mention, I went ahead and lowered some more.

My fronts are now 9 threads from the bottom and I noticed a noise had developed. After a good inspection and some turning of the wheel I noticed the top ball of the drop links fouls on the plastic arch liner causing a bit of a muffled scraping sound, the sound is most audiable when hitting a bump on full lock as it 'twangs' the plastic on the 'seam' where the two liners join.

I guess its a function of the way the attachment wings are raised to allow the use of standard length drop links which is why it doesn't happen on coilovers which require the use of shortened drop links.

Just thought I'd post my findings as it may help someone to stop being as paranoid about their suspension noises.

thanks for the info, any findings are worth spending a minute to read imo