I bought the p160, and love it. It looks great, airflow is awesome and the things they have in the case aimed towards silence do a great job. I have my harddrive just in the mounting slot on the rubber mounts and it doesn't vibrate my case at all.
The top front usb/firewire and temperature sensors are extremely nice and add to this case a lot.
I don't like the p180 for it's higher price, I don't like the door for the front and I think the P160 looks a ton better. I mean a case is a case, and I wanted one that I thought looked cool and the p160 had great features for it too.
I recommend it!