The snow in the photo was only a couple in inches deep on a flat stone. Even then this setup boiled about 1 litre of water in around 23 minutes at a temperature around -6 C. The Trangia burner did take about 2-3 minutes to jet properly though.

It was a test to check sub zero alcohol stove performance. To improve cold weather temperature performance using this Trangia setup I would now place a Snowpeak Ti plate and Trangia primer pan from a Trangia winter attachment underneath the assembly. A little bit of insulation under the ti plate would help with efficiency as well.

http://www.youtube.com/watch?v=kuvCxjFgKWw

Personally I still haven't yet come across an alcohol burner that outperforms the Trangia burner in terms of overall performance, usability and flexibility and cost. The ability for the Trangia to store residue fuel internally is a major plus.