I recently bought an LX3, mainly because I was interested in shooting at higher ISO ratings. I have been using a GX100 for a year, which was a great camera but which wouldn't give a decent image at over 200ASA.
These b/w pics were all shot as Jpegs at 1600 ASA in dynamic b/w mode and tweaked a little bit in iPhoto and P/S Elements6.
The colour shot is 3200ASA.
I am pleased with the results.