This guy actually did a pretty good comparison trying to use the same set of variables on 6 different popular caned "penetrating" oils. All while recording his results and using a spread sheet to graph them all out. His findings show Liquid wrench as the top performer and also is the most cost effective.
That said, I normally don't have the luxury of letting anything soak for days, let alone hours when I am working. What >I< look for is something convenient (and cost effective) that will lubricate the fasteners once I break them loose, more than any "penetrating" characteristics. (Also that will not spill all over my truck / tools, that I can toss around) And to prevent metal on metal galling on certain pieces of equipment.
BUT, normally when I drag a dead bike home, I do try to soak the entire thing in some sort of spray on "penetrant" depending on what I have handy at the time.
Great video!