Double-butted.

On my disc-brake commuter I run DT Competition (2.0/1.7) on all four sides. On my backup commuter I run DT Revolution (2.0/1.5) on three sides with DT Competition on the drive-side rear.

Both wheelsets are very strong, very durable, and very comfortable.

Except for "Man, they're cheap", I haven't heard a good argument for straight-gauge.