Support for the "none" cipher, i.e., for unencrypted SSH connections, should be restored.

I tested the data transfer speed when using SSH with the arcfour cipher between two servers on a gigabit LAN with 2.4GHz CPUs.  The transfer speed turns out to be around 30MB/s.

30MB/s is fine when you're transferring over most WAN connections or when you're transferring across a 1Mbit network or even a 10Mbit network.  In these scenarios, the SSH transfer speed is still faster than the network speed, so SSH introduces no delay in the transmission of the data.

However, gigabit copper is becoming ubiquitous, and even fiber to the desktop isn't so uncommon anymore.  Every computer at my company has a gigabit NIC plugged into a gigabit switch.  In a gigabit environment, an encrypted SSH transfer using 2.4GHz CPUs, which are hardly slow or obsolete, is 70% slower than an unecrypted transfer would take.

When I'm transferring a big chunk of data across my corporate LAN, I don't need for the data to be encrypted.  All I need is a way to initiate the connection securely.  SSH can provide that, but it sucks big time that after the connection is initiated, I have to sit around twiddling my thumbs waiting for a transfer that could be going more than three times as fast if it weren't for the unnecessary encryption.