iJournal and Xjournal are the two biggest OS X clients, from what I've seen. LiveJournal's MacOS Download Page lists the common popular clients. Personally, I still prefer the web interface (and if it's a big entry, I clean it up in vi — the Unix visual editor — first), though.

Speed of copying depends on how you're doing it. Are you using, e.g., something like scp or sftp, which encrypts before sending? Or FTP, which opens a new network connection between devices for each file? Or a straight copy as if you're using networked file systems a la NFS or CIFS/Samba? Are you entirely wireless (and if so, 802.11b (11Mbps, Airport) or 802.11g (54Mbps, Airport Extreme)), or wired (10MBps, 100MBps? hub/bridged, or switched?)? Or iRDA or Bluetooth? (I know, "Gesundheit.")

Some other key sequences that may come in handy are [Command]-[Up Arrow] for "Jump to beginning of text box" and [Command]-[Down Arrow] for "Jump to end of text box."