Things I liked: It is great in areas of spot rust as long as the spots are not too large. I have found that I can get the darker finish with multiple coats of the liquid; however, I am still trying different techniques. It does give an initial one-coat deeper finish. Obviously the paste makes more of a mess than the liquid.
Things I would have changed: nothing, except it would be nice if it was less hazardous.
What others should know: Should be already known, but cleaning and preparation is 90 percent of the work. Patience is the remaining.