LOR was chosen because it could be done with a single launch of the Saturn V. The single launch requirement was mandated by the fact that, when the mission mode was decided on, we had zero experience with spaccraft rendezvous and docking.
[interesting since the LOR requires two dockings, while EOR requires only one, or more, but I think the 'selected' mission was Direct - GES]
If you are using smaller-scale rockets for a manned mission, with a 8:1 or more LEO mass:Lunar Payload Delivered ratio, you will get a much more robust vehicle if you can do EOR. This fairly screams for a reusable shuttle which is not as complex to operate as NASA has made it seem. A small fleet based on modular elements operated incycles will do the job. Individual payloads can be around 2500 kilograms with maybe ten assembly flights plus the crew delivery. (The operative point is to keep it small-scale.) That sounds expensive if you are used to thinking in terms of assembling a new spacecraft from scratch with every launch. If you are only servicing the same spacecraft, your only real expense, between flights then you can realize savings over long term.
If you are expecting more than two or three flights to the Moon per year, you would be wise to establish a spacecraft storage facility on orbit, particularly if you only have one launch pad on Earth to start with. This is only a step away from being a propellant depot and, much later, a servicing center.
I am a rather large fan of the concept described in RAH's "Space Jockey" three separate craft to do three very different jobs, but it will take time and infrastructure (= $$$M).
I would like to start developing that infrastructure once we build the Outpost and start servicing it. Once we start bring people and hardware out there regularly. I'm not sure how we can afford it in the meantime.
Just my own thoughts, that may or may not be right, and I certainly do not speak for the group in this.
--Paul 03:43, 9 October 2008 (UTC)