Very nice, are they corrosion resistant? i know alloy over time can get the white powdery deposits and eventually eat through, i think if they anodize it correctly this is not an issue.I have a custom cabinet shop, bought our own building a few years ago and wanted to set it up "right" since it is ours, not something we rent. We used the Kaeser brand "smart pipe" it is aluminum, very easy to install and work with, has special fitting that don't require sweating or threading and it is easy to add on to, etc. Not cheap but when you consider the labor savings on installation it was worth it.
Way down at the beginning of our blog there are some pics:
http://ancomcustomcabinets.blogspot.com/search?updated-max=2009-10-16T09:01:00-04:00&max-results=7
Nict fit out in the shop though