Its funny, when I got my first handgun I was looking into cleaning products wondering which was the best. All I heard about was Hoppe's 9, over and over again I heard it. After using it over the summer in my EDC I can confirm is is a very fast evaporating oil. I take my pistol down every two weeks to reoil, and it does fine if you do that. However it is not for the person who may pack up there pistol 3-4 months at a time before shooting or maintenance. In short, if your going to the range the next weekend and do a pre cleaning and lube, its fantastic. But don't trust it over about the three week mark, most of it probably won't be there anymore.
Currently I have gone to using a combination, both grease and hoppes9. About a 60-40 split favoring hoppes9. Depending on the part. Most of the parts in my fire control group still get hoppes, the barrel lug and the sides of the lug now get grease. Top of the slide where the barrel rubs gets grease as well, along with the rails.
Hoppes9 now goes only outside the barrel forward- of the lug, fire control group, light coat inside the barrel, magazine springs and body of the mag. I use clp on the external of my slide to keep the finish protected. Everything else now gets grease.