I've got the Bilsteins set up with the stock springs on the lowering perch, and I can say that I personally like the balance between looks and practicality. I used to have OEM struts with Eibach's (1.2 inch drop), and the front chin spoiler would scrape way too easily. The H&Rs at a 1.5 inch drop look even better, but would obviously scrape even easier. The lower you go, the better it looks, but I personally wouldn't want to go lower than the Bilsteins with the stock springs on lower perch.
That said, my only disappointment after my conversion, is that the front end looks a little higher than the rear, when looking at the gap above the tires. I wish I would lower it just a hair more. Overall I'm happy though.