Thanks for the info - my question was genuine (for a change) rather than a complaint. I am very taken with the idea of the amp, and was just considering cab options. As it happens I would probably only ever get one cab: but this way I could get two 8 or 4 Ohm cabs, and the DG amp would still cope.
*goes to check Maths on 1x 8 & 1x 4 Ohm cab...