Hi...
Ya I finally got the lens for USD360 about a month back. And am pretty happy with it so far.
I went to the geysers areas. No where near any mountain, but the temps were pretty low still (-2 to -4 C at night
).
The 20 mm served well, though i found myself scrambling for the 40-150mm lens often while spotting wildlife and far off hotspots, then switching back to the 20mm for the nature shots. The usual kit lens was relegated to the depths of my back pack. There were wide salt basins, and valleys where ppl with Canon 10-22mm dslr lens were better equipped. But i got the memories somehow with my mobile cam's panorama mode.
I visited a couple of museums after that, where flash photography wasnt allowed. The fast lens came in very handy there. I will post a few pics as soon. I am reluctant to put any more personal pics on my office laptop. Its a one way ticket. Dont have any way to taking it out later.
So am waiting for my own laptop to arrive in a month's time.