The RAW files from the D-Lux 3 and the LX2 are exactly the same. There is supposedly slightly different processing involved with jpegs and apparently the LX2 allows a higher max ISO than the D-Lux 3.
I had a D-Lux 3 that I had received as a gift, and LOVED it. The level of manual control it gives you is fabulous and the joystick controls make it incredibly simple to change settings quickly. I wish my dSLR was set up as intelligently. Yes, it is noisy at higher ISOs but the 100 and 200 ISO files are to die for and with IS I was able to handhold some pretty slow shots. I used RAW for everything except casual snapshots. I found that even the RAW files needed very little post-processing.
There are two things I would change about the camera if I could. First, I would get rid of the protruding lens barrel so that it would be more pocketable. The protuding lens barrel does make a big difference in terms of stashing the thing in one pocket or another and makes it difficult to find a camera case that fits. Second, I would have an auto lens cap and not a separate lens cap that needs to be manually removed and that can get lost (very annoying). Other than that I had no complaints. Even the time between shots shooting in RAW was quite acceptable to me, but I tend not to need to take many shots in quick sequence. Some examples here (the first two shot in RAW and the last as a jpeg):
http://www.flickr.com/photos/soloriver/362874659/in/set-72157600005622875/
http://www.flickr.com/photos/soloriver/343482641/in/set-72157600005622875/
http://www.flickr.com/photos/soloriver/362874658/in/set-72157594491325066/
Personally, I think any small digicam makes a poor "stealth" camera because generally you have to hold it up and out in front of your face to take a photo, but to each her own.
My D-Lux 3 was stolen (I got mugged) and I would LOVE to replace it with another one, because it was sexy and black and gorgeous, but given the $250 price difference I have ordered an LX2 instead, in silver because I think the LX2 looks better in silver than in black. Same camera, different outfit, I'm sure I'll be just as happy with the images.
For me the GR-D was a no-go because of the slow RAW write speed and because I think it's butt ugly. As far as I know, no other small digital cameras shoot in RAW so I did not seriously consider others.