This is a great chain lube, I've tried white lightening and a few others. But this is much better if it is applied correctly. You "MUST" drench the chain, spin it for a few minutes to work out some of the grime, then clean it until it can't be cleaned anymore.
I commute and mountain bike on the same bike, so I ride several hundred miles every month (its also a 1x9 drivetrain so the chain sees a lot of flex). I live in Oregon and we get a lot of rain here, making trails muddy, and the bike sits out in the rain between my classes. If its raining everyday the lube lasts about 2-3 weeks before the chain starts to get loud; if the weather stays dry it can easily last a month or two.
I've never had problems with my chain rusting. But I've heard this only happens if you ride in well below freezing conditions.
Best general chain lube I have found, and believe me I have tried many. Recommend cleaning chain with Pedro's or other chain cleaner, dry well, then apply. I am a bit obsessive and try to make sure I get the lube into each link. Shake well, and give it a couple of minutes to soak in, then wipe of excessive. I try to lube every 100-200 miles or after a nasty wet ride. I have been getting 3000 miles from my chain with very little stretching. One of the less noticed benefits of this lube is that it "forces" you to take a close look at your total drive train which helps you spot any potential problems.