And don't forget that 11g doesn't give you 5MB/s as the 54Mb/s may indicate. On a standard 802.11g network you'll get around 22Mb/s, i.e. around 2.7MB/s theoretical maximum transfer rate.
My N900 seems to get around 650KB/s from a real ftp server, most of the time. Peaks are a bit higher, but...