Ghost Solution Suite 3.0 HF3 and later versions of Ghost solution suite no longer has the option to select the level of compression during a Create Disk Image task. Prior to HF 3 the level of compression was available to be selected.
This functionality has been placed back in the product as of Ghost Soulution Suite 3.1 MP1 see the releas notes for more information.
As a workaround in version prior to GSS 3.1 MP1 there is an option to add a command to the "Additional Parameters:" that would allow the compression to be sent at a command level.
At the end of the Additional Parameters line put in a space and then -z1 or -z2 to achieve the level of compression that was previously available. For more information on compression see