I do love Transmit for its smart Finder integration, e.g. mounting remote hosts as “disks” within Finder or quickly opening connections saved as droplets directly from Spotlight.
But… I was quite shocked to find it takes Transmit 10 times longer than Cyberduck to transfer text files when using SFTP – 2 minutes instead of 12 seconds for a 20+ MB server.log via a 2 Mbit line (I know it’s slow, it’s not mine…) 😡
It took some time of fiddling to uncover Transmit uses OS X standard ssh configuration settings as defined within ~/.ssh/config or /etc/ssh/ssh_config.
Thus I created ~/.ssh/config containing
Host * Compression yes CompressionLevel 9
et voilà, Transmit now compresses files on-the-fly as well 😀