I put 8' double high output (HO) vapor tight fixtures in my shop and I'm VERY happy with them. Since they are vapor tight, no dust gets in em and therefore no cleaning is required...ever. They are pricey relative to the cheapy 4'ers that you can get but as my friend Bill says...you get what you pay for each and every time.
These vapor tight HOs put out a boatload of light and I like them. I did not spring for the ones that start up quick in cold weather (can't remember what that change actually was) so they flicker some when they first start (only when its cold out) and they do make some hum noise. I have not yet replaced a lamp in any of them and it's been six years so I'm happy with them.
