"The current EMU's PLSS uses ice to cool the person inside."

Really? Hmm. Got a link for this? And what affect would this have on Mars suit design?

"I don't think you are the expert on comms on Mars. Neither am I, but I have read a dozen or so papers on the subject. The Moon has no chance to use propagation at low frequencies, Mars does."

No. I don't claim to be an expert. Larry J would have significantly more expertise in this area. But I have some comments nevertheless. One obvious point is on the moon you could have line of sight with Earth. Another point is that Earth/Moon L-1 could also be in line of sight and have less delay than boucing off Earth or any satellites. {I have also read that there is some kind static field on the Moon- I have never heard anyone mentioning using this for communication purposes, but might be possible.} As far as low frequency transmission, I guess it would depend on how much power was used- for portable use I don't think it's practical. Before cell phones and satellite phones, there was limit on radio distance. If you are talking about distance of say 10 miles it's not going to be a problem- but having atmosphere or no atmosphere isn't relevant.
Another point is you can use relays located on mountain tops- as is done here on Earth.

"The Moon can't over time retain satellites without massive fuel reserves, Mars can use COTS Comms SATs or GPS."
Satellites at L-1 don't require massive fuel reserves. The Moon always faces the Earth (and L-1), add one relay for given area of say hundreds of sq miles of a crater and you could radio to Earth and L-1, add a solar panel which rotates facing the Sun (every month and 365 days) and you have a power supply. This relay (which is located at one of highest point in the region could also relay to other locations in crater.

"Geoff, my point about the waste of time it would be trying to test Mars Systems at the Moon was directed at all the nonsense posted by the other lunies above your post... I was being lazy..."
Ok

"I think this Moon or Mars thing is all mute. Without a good political reason for going neither the Moon or Mars will soon be a target for NASA's Code M."
Code M?
One thing that the Mars supporters should realize is that exploring to Moon to determine if there are minable deposits of water, is IMO the fast way to actually get a Manned Mars Mission. And it's the political viablity of going this route that I think of as it's most important aspect- "getting into space" is fundementally a political problem, rather than a technological problem. [And making a NASA lunar base is not what I'm talking about.] I'm talking about a low cost PROGRAM to determine whether there is commerically minable deposit of water. I really don't care how this is done- as long as it's done throughly [as far as answering the question]. What I mean is, I think, that a manned aspect is needed, opposed to using only robots, and a manned aspect of lunar program would be "helpful" in terms of Mars exploration and also in terms of actually minning lunar water (a manned mining operation should be cheaper than trying to do it solely via machines)
Two political dynamics why a lunar program gets a quicker Manned Mars:
A manned Moon is a smaller step- therefore requiring less govt funding and a shorter horizen before completing program- roughly 5 years & 5 billion.
Second part is if there is minable water on Moon, business interest will want a bigger market for lunar water- NASA doing a Manned Mars could be a significant customer for lunar rocket fuel and water.