From earlier post. Larry J said:
"Honestly, I have not looked into L1 as a gateway. I choose LEO simply because it facilitates transfer of personnel and equipment and makes for a good starting point. I wonder if O'Neil's L5 might be a better choice than L1. I think it'd be easier to send materials from the moon to L5 instead of L1, but I don't have any numbers to back up that assertion."

It is my understanding that in terms of delta-v, the difference between all L-points [Sun/Earth and Earth/Moon] is small- by using gravity of Moon to assist, one can with about 50 meters per sec delta-v get to any of other L-point- though you would have limited "launch windows" and circuitous trajectories using "fuzzy boundaries". And for instance my "take" on the rescue of the AsiaSat by Hugh demonstated that it's possible to get from a L-point to GEO using relatively small amounts of Delta-v. [In other words, as far as delta-v needed, all L-points require about the same delta-v to get to from Earth or from the Moon. I also see little difference between any High Earth Orbit or High Lunar orbits and L-points and I regard EML-1 & 2 as a kind of highly elliptical Lunar/Earth orbits that have a tendency to kinda "stick" at their apogee.]
I think if you want to put a big rock (or space colony) at some L-point and you want it to stay in one area for decades of time, then EML 4/5 are good locations, whereas EML 1 & 2 wouldn't be stable enough unless you have some kind of station keeping. And I would guess that station keeping at EML-1, would NOT be trying to keep in a exact location or point, but rather you would "set a course" which optimized various factors- such as using the least amount delta-v for station keeping, avoiding getting in the Earth's shadow, perhaps even extreme example going behind the Moon in order to block some of the affects of a solar flare- or similar move could part of docking with spacecraft coming from Earth or the Moon.

EML-1 is the nearest L-point to either Earth or the Moon. From the Moon, EML-1 is nearly a escape trajactory of the Moon. From Earth, swinging by the Moon, and braking less than what's needed to enter a low lunar orbit, but braking more than a return trajectory to Earth.