Well, I went and visited his website, and looked through his section on ISRU. It did little to dispel the impression that I had from his Space review article that he really is more focused on Mars ISRU than Lunar ISRU, and my supposition is that perhaps he sees the idea of cislunar development as a delay in the application of his particular field of interest.

"Most discussions of lunar ISRU seem to assume that resources are readily available, and they proceed to emphasize processing, while minimizing logistics (excavating regolith, regolith transport, deposition into and removal of regolith from reactor, dumping waste regolith, etc.) However, the quantity and composition of end products provides the entire basis for considering the use of lunar ISRU, and for setting the requirements for lunar ISRU systems. Therefore, we begin here with the potential end products."

This is the same point he makes in his article. There are only six cites in the Lunar ISRU section, only one of which could really be considered an ISRU paper ["Development of the Moon," by M. Duke, L. Gaddis, G. J. Taylor and H. Schmitt, http://www.lpi.usra.edu/lunar_resources/developmentofmoon.pdf]

The 1988 ISU study "International Lunar Initiative Organization" has a nice basic overview on "Mining & Beneficiation" and suggests a Mobile Excavator and a Three Drum Slusher (my preference). The 1985 book "Lunar Bases and Space Activities of the 21st Century" looked at "Mining for Lunar Base Support" and "Electrostatic Concentration of Soil Minerals". In 1999 Schrunk, Sharpe, Cooper & Thangavelu published "The Moon: Resources, Future Development and Colonization" which featured an entire chapter on mining, transport & beneficiation. I especially like the rotary wire brush idea, which might be adapted to a slusher bucket mechanism, and which I think will be important for deeper regolith excavation, where it gets really compacted. Peter Eckart's 1999 "Lunar Base Hndbook" specifically addresses Lunar Mining Equipment, and notes a survey of mining equipment [Gertsch, 1996] that breaks the possibilities down into five major categories:
-Dozers,
-Scrapers,
-Trucks,
-Front-End Loaders, and
-Hydraulic excavators

Neil Ruzic's speculative 1970 work "Where the Winds Sleep" mused on some of the possible extraction and beneficiation technologies to be developed on the Moon. Harrison Schmitt's 2005 "Return to the Moon" has a nice section that treats "Equipment Design". NASA SP-509: Space Resources has a section by the Gertsch noted above on "A Baseline Lunar Mine". I think this is where I got my preference for the slusher-bucket operation. It is so simple it is difficult to break. It doesn't need to be a high mass object because Lunar rocks can be used as ballast. PERMANENT looked at mining the Lunar surface and also suggests a slusher bucket. John Lewis's (ed.) "Resources of Near-Earth Space" talks about "Mining Applications in Space" and suggests a number of strawman excavation and transport methods:

Excavation-
Front-End Loader
Clamshell
Dozer
Continuous Drum
Scraper
Slusher
Backhoe
Bucket-Wheel Excavator
Dragline
Explosive Casting
Auger
Rotating Brush

Transport-
Conveyor
Cable Tram
Rail Tram
Pipeline
Maglev Containers
Ballistic throwing
Electrostatic Transport

Like I said, I don't think he tried very hard to find research on "logistics". Oh, and I'll also note that NASA did recently have a contract with the Caterpillar Company to study exactly this topic. It was cancelled under Griffin. My view of Dr. Rapp's agenda is reinforced by another statement he makes in the context of delivery of Lunar materials to cislunar space for materials science purposes:

"...there would still be few products valuable enough to merit the transportation costs of the raw materials into space. The Materials Processing in Space Program has yielded very little after 30 years of effort. Industrialization of space appears to be a long way off."

Which appears to ignore the fact that NASA and the shuttle program, post-Challenger, have made it very difficult to make advances in that regard. There is after all a market for high altitude suborbital rockets for brief periods of microgravity. That's also why we have drop towers around the world and airplanes that fly parabolic flights. Materials scientists are trying to make advances, but they've been hampered by the difficulty of not having had regular and frequent access to a long-duration orbital facility in the last 30 years in which to conduct on-going research. I feel it is grossly unfair to dismiss the materials science possibilities on that basis, especially when I'm sitting here looking at a 600-page book on "Space Industrialization Opportunities" published in 1985. Back when people were still excited about the prospects that the Shuttle was helping to unleash. Looking through the "1981-1999 Space Shuttle Mission Chronology" it's easy to see that there was a lot of exciting stuff going on. But the private stuff kind of peters out in the early 1990s when NASA really shifted its focus to a space station.

So that's why I thought the article was weak. I think I've offered strong support for my opinion, but I know you'll disagree Chris. One thing I do know is that it is going to be very difficult to develop cislunar space from Mars. And cislunar space is where I see the action as being.