Kind of hard to say, actually. I'd say they're roughly even, at least on the bass here at the shop. Both pickups are under direct pressure, which normally results in more output compared to a pickup that is "stuck" or clamped on. So in that way, they are in the same ballpark.
But it's kind of like apples and oranges, since the character of the tone is rather different. The FC, IME, has more mid presence, while the LL has more low end girth with a less midd-y character. So the differences in ACTUAL volume (measured on a sound meter) might not necessarily correlate to the PERCEIVED volume, especially once you put it in context with a band and start tweaking EQs to get the tone you like.