Why does everyone say you can't compare the two things. I think anyone who says that has a too fixed mind, especially if the question is "which one is better?".
In economics there is a term utility. It means the benefits you get out of something. There is the utility you get out of LFS and the utility you get out of GPL. How to compare utility? Obviosly, you would be willing to pay more for the thing that provides most benefits=utility for you.
So all it can be boiled down to is: For which one you would be willing to pay more money for? Its like with apples and oranges. Which one is better for you? The one for which you would be willing to pay more money for (It's not really a money-thing. Money here represents everything else you are not buying to buy the apple/orange - the more things u are willing to give up the more valuable it is for you)
I would say I'd be willing to pay at least 20x as much for LFS as for GPL.
What about you?