Pt. 1 - Appearance and Zoom Range
Pt. 2 - JPEG Noise
Pt. 3 - ISO 80 JPEG Crops at 35mm & Full Aperture
Pt. 4 - Flare Performance
Pt. 5 - Noise Performance Revisited
Pt. 6 - G7 Default JPEG vs GX100 Silkypix Conversions
Pt. 7 - Key Timings
Pt. 8 - Build Quality, Quality Control, and Battery Life
Pt. 9 - Conclusion

Disclaimer: This section, while important, is extremely subjective. All I can tell you is of my experience with a small number of samples of these cameras.

D-LUX 2
Build Quality - The D-LUX 2 build is very nice with a light but solid feel. It has a metal body with only limited use of plastic.

Quality Control - The one copy I have tried of the D-LUX 2 has been flawless.

GX100
Build Quality - The GX100 build quality is also very nice. It also has a great, solid feel. Both copies I have owned have had wobbly lens assemblies, which perceptibly shift even when the camera is inverted a certain way with the lens assembly retracted. The zoom control on my second copy also has a bit of an inconsistent click, which is a minor issue but worth mentioning.

Quality Control - The first unit I bought was purchased new but had signs of use. I cannot say for sure that it had been used and returned, but I suspect that it was. At any rate, that camera did not function properly. It may be that the original owner dropped it or damaged it in some way, so I want to be careful not to say much about Ricoh QC based on the one unit. The second unit, incidentally purchased from a different seller, has been perfect.

G7
Build Quality - The G7 build feels the most solid of the three. While the D-LUX 2 may look more luxurious (especially to "Red Dot" fans), and the GX100 may feel more luxurious, the G7 definitely feels the most substantial of the three. It is by far the heaviest. Even the battery and card door mechanisms feel durable, which I can't say for the other two cameras.

Quality Control - Unfortunately it took me three tries to get a good G7. The first one I bought new had multiple white hot pixels in the center of the sensor, apparent even on very short exposures. The second came with signs of use, large debris (not just dust) inside the front lens element, and at least 5-6 stuck or dead LCD pixels (I don't go looking for these and in general am not troubled by them). The third has a couple sensor pixels stuck on blue, but I am not troubled by them. Much better than white. The other thing I noticed is that the amount of viewfinder inaccuracy was not the same on the three G7 units. The third had less parallax error than the second. I should mention that the "good" G7 was purchased from a different store than the first two.

Since I don't feel that I can draw any solid conclusions based on these few experiences, I won't say here where I bought the units that had problems. I will say that the sellers involved were prompt and professional in issuing refunds or exhanges as requested.

Battery Life
I will report here my subjective findings since I don't plan to do any formal testing. Battery life is not a strong point for any of these three cameras. Compared to my previous compact camera, a Fujifilm Finepix F30, all three of the currently compared cameras have poor battery life. Compared to one another, the G7 seems a bit better than the other two. Subjectively, I get a full day of intermittent shooting with one G7 charge, whereas the GX100 and D-LUX 2 have me turning to spare batteries part of the way through the day. With any of these cameras, an extra battery or two will be needed if you plan to do a lot of shooting.