Ice (snow) versus water (at freezing point, but still liquid water) makes a HUGE difference. Melting that ice/snow requires the same energy as raising the temperature from 0 to 60 deg C (140F).

And yes, in anything but totally still air the performance of the windscreen has a huge impact on the result. That goes with all stoves, but the effect of wind screen design is so much more apparent with low effect alcohol stoves. Which is why I love the trangia cookset design... (Use a different burner in that design and then you can talk about performance... but let's not distract, shall we?)

Also, I want to apologize for clogging the debate with safety of alcohol versus other stove types. That discussion is worthy of another thread, but here it is only a distraction. I'm a big fan of informed users making rational risk assessments. I don't have anything against alcohol burners themselves - they're fine for what they are and what they do. But I do think a large number of people use them with only a faint idea of what they're dealing with. But this forum does not fit that description, so let's move on...

I'm anxious to see more results!