Well, I don't really play multiplayer matches much; I like to be able to play with friends in the same room, preferably on the one console (Raagh, whatever happened to 4 player split screen? and why did LP2 screw up it's split screen so hard?). However, I do find some pricing and such to be ridiculous (12 maps for $45, some of them possibly being old ones WaW?) and most of the time the developers make good enough maps that to include the new ones that were never there in the first place is redundant.
But like other people, if they're free, I support it and therefore would download it, and a community based map making thing would be a great thing to have. Showing how much talent the consumers have, and possibly inspiring companies to build and improve on their games, while the community gets more variety.