Things I Don't Like
1) Colours wash out somewhat near right side of histogram. More than a SLR anyway. I suspect the sensor has some kind of compression near the clip point. It creates a more filmic native response, but I'd rather have the sensor be more linear so colours are true right across the dynamic range.
2) Probably two stops noisier than the D200: about the same noise at ISO100 as the D200 at ISO400. This is to be expected, but it means being careful with exposure. Post-processing noise removal works nicely to eliminate chromatic blotchiness, thankfully. The luminance noise that remains is pleasingly grain-like, and unobjectionable.
3) Mechanical sounds are misleading. The camera is silent when making the exposure and clicks twice when it is complete. This is because the CCD purge is electronic and instantaneous (so the shutter can be open already at the start of the exposure), but it takes a finite time to read off the sensor data so the mechanical shutter must close during read-out. This is still throwing me off because I think the shutter has terrible lag ... but it doesn't. I'll get used to it.
4) Manual focusing could be better. I would like more maginification in the close-up window; the 2x view that is now provided is insufficient for critical focusing. There is a function to perfect the manual focus automatically, but it rarely does a good job.
5) No absolute Kelvin white balance settings. I want to set the camera to 5300K and leave it, but this isn't possible. Daylight seems to be close.
6) Wide open isn't very wide, effectively -- 2.8 still doesn't do much when the lens is this small. Still, when shooting close, you do get some very nice bokeh. This is a format limitation as much as anything, so it's nothing Canon could have improved.
7) I want a wider lens. The camera goes pretty long at the telephoto side, hitting a 210mm equivalent with its 6x lens, but it starts out at 35mm equiv. I'd gladly trade everything beyond 100mm for a 28mm start. I'd be thrilled with a 24mm-80mm range on this camera, but that's not what's offered. Apparently you can buy a 0.75x adapter, but that makes the camera much heavier and absolutely non-pocketable.
8) LED indicators on camera body that serve no useful purpose. This is a quibble, I guess, but the mode and ISO dials have little LED indicators that show the position currently selected. But, in the dark, these LEDs don't illuminate the actual setting that has been chosen -- the dials are opaque machined aluminum, and all the LEDs illuminate are the knurled sides of the dial. Wha?
9) Focus assist illuminator beam too narrow. It just lights up a little spot, rather than a wider area. If you're shooting at anything other than portrait distances, the illuminator doesn't help at all.
10) Buttons sometimes too hard to press. It keeps them from being pushed accidentally, but some buttons are too recessed to easily activate. And just forget about using it with gloves/or mittens.
11) Optical viewfinder is a crock of shit. Total waste of space on the camera; image coverage is maybe 80% and is horribly offset. The only reason I can think of to use this instead of the display is if you are stuck in the wilds of Borneo away from a battery charger and want to get 600 shots instead of the ~300 shots you'd get when using the 260K pixel LCD screen as a viewfinder.
12) Image review only goes to 50% data. You don't get to see demosaiced pixels even at an apparent 200% zoom setting. This is annoying when critical sharpness is important, but usually not an issue as the sharpness generally is there in the raw file.
Things I Like
1) Focus bracketing. This is an exceptional idea. It should be in every dSLR. The camera will tweak focus slightly and take additional exposures so you are almost certain to get a very clean shot when critical focus is important.
2) Snappy UI response. Very quick image review and zoom. Many useful ways to navigate around in the image. Very rarely am losing patience with the camera.
3) The rotating wheel control; similar to wheels on DSLRs but flat on the camera's back. Very well used for setting exposure controls and navigating the camera's menu system. Also used for manual focusing.
4) Lots of shooting customization options. Including two dedicated mode wheel stops for customized "scene modes" if you please. It will even copy/paste from any current shooting configuration to one of those custom banks for tweaking and optimization.
5) Built-in 3-stop neutral density filter. An actual filter clicks into place inside the camera when activated. Brilliant idea: allows wide aperture shooting in full sun. And you'll never lose it, and it'll never get smudged.
6) Image stabilization that works. At least two stops of sharpness added, sometimes three. Very well done.
7) Scary sharp lens. Once properly focused, the lens seems to resolve the sensor at all apertures and zoom levels. Can't ask for better sharpness than this. Minimal chromatic aberration and purple fringing even in extreme situations -- and although CA is not completely absent in high contrast situations, it is very easily correctable. Barrel distortion is quite minor. The lens is fantastic -- spectacular even.
8) Somewhat usable ISO1600. It's even noisier than the Fuji F10 or F31, but it can be coped with if you understand what you'll get. Nevertheless, for work where noise is unwanted, you want ISO100 or lower.
9) Outstanding macro capability. It will focus on the printing of paper pressed up against the lens assembly (backlit).
10) Size, weight, design, build quality. It looks, feels and hefts like a serious tool. Lots of machined metal, not much plastic. As long as I keep the dust out of it, I have no reason to doubt it'll be working for years. (N.B. the LowePro Rezo 50 zippered bag fits the camera perfectly and protects it nicely.)
11) Creative controls. The camera was designed first as photographer's tool; it has mode settings for M,Tv,Av and P and provides hard buttons and knobs needed to adjust most traditional photography settings very quickly. It even has a "custom" button you can assign to various menu-only options such as WB or the ND filter. It also has Scene settings for quick adjustments when you don't want to fool around -- and the manual explains in detail what each setting does differently.
12) Manual exposure mode kicks ass. Activating the live histogram gives you a real-time indicator of exactly what is going on with the exposure, so you can very rapidly fine-tune what the image will look like, taking "zone" shooting to its almost ultimate destination. (Any good DSLR with live view histogram can provide this, that it's available in a pocket shooter is fantastic.)
Conclusion
I'm happy with my purchase, and I would buy it again. I don't think there is any camera on the market that can directly compete with it, even for 2x the price. The lower-end Leica/Panasonic models are too long-in-the-tooth to compete on features and noise, even if their lenses are comparable. The Leica M8 costs 10x this amount.
And while you can buy the cheapest DSLR and a cheap consumer zoom lens for just slightly more than the $550 it cost me, that DSLR weighs more and is far bulkier and not a "pocket" camera at all. (And, of course, the DSLR will have a much larger sensor and thus much less noise. That's the trade-off.)
I recommend it as a pocket camera for those who are willing to use the camera to its fullest. Don't buy it if you are going to use scene modes all the time or pop-off snapshots at the zoo; there are cheaper cameras that will make you happy. Get it if you find yourself always making a choice when leaving your house to "take the big camera bag" or "go without a camera." With the G9, then, there's no reason to ever go anywhere without a camera.