uhh... 512x512 is perfect, you see the detail you need to see, up close it may not look to close, but i can't remember the last time i was right next to someone an entire race
doubling the texture size will most likely triple or even quadruple the space size; thus eating up bandwidth for the devs like no other, require a LOT more space for the devs and especially us, and it will take much much longer to download, and most likely boot some people off the server because of so much lag from downloading the skins
-1
if you know 'em, have them send the skin to you, problem solved right there