Having owned manuals for 6 years and now owning a DSG, I can safely say the DSG is far better in the snow for starting off. I had no wheel spin what so ever it was brilliant.
One thing i will say is stopping can be a bit hairy in the snow as i found out today. In a manual you can use the engine to brake via the gears, in DSG it does it slightly but no way as much as you can in a manual. The poor ABS was working over time this morning.