The download includes a lot of maps that (as far as I can tell, and from what I understand) are not RMF capable. Looks like they just zipped up their entire map directory. I could be wrong, but if that is the case, then no, the client downloads will not be as large..
Pagan, if it is a mutator, what name did you give it and what options/variable (if any) did you include in the server's .ini file? Or did you just load the files into their respective folders and fire it up?
Are they even offering this up for other servers to run at this point? I got the impression that they are looking for players.
Floyd