As a GX100 owner, I agree with your conclusion--that it is better to wait for a better camera of this genre--though for slightly different reasons than you've stated.
The so-called "grain" issue does not bother me - when the GX100 is working, it produces images that are of quite satisfactory quality (to me), though I find the image quality to drop off at the very modest 72mm maximum zoom focal length. That was a bit disappointing, as 72mm is pretty close to optimum portrait focal length (85mm for me). Tolerable, though.
What DOES bother me is the price-performance-quality equation that is at the heart of your question.
I came to the GX100 via the following route: For 30 years I abused and loved Nikon F series film cameras. Lugged 'em around in special LowePro backpacks and was NEVER let down. I started with digitals in '99 and went through a number of them before settling down for 3+ years on a full-manual Pentax 555, which I still use. I got the Pentax because I was tired of lugging around all of the big stuff, but still wanted full manual control and the ability to pocket it (kind of) when doing motorcycle rides. The 555 fit the bill perfectly...except for one thing: It's shortest focal length is 36mm, pretty much standard for the so-called P&S cameras.
I had been waiting for several years for a camera that had true wide-angle (i.e., without having to attach adapters), high image quality, easy portability, and build quality sufficient to survive careful but robust usage. I did not really care what the price was, as long as it met those criteria.
I came very close to going with the Olympus 7070 or 8080 - both just a little bigger than what I wanted. The Sony R1 met the wide-angle criterion, but was also bigger than what I wanted...and expensive. Panasonic got very close to capturing my money with either the LX1 or LX2, but the bad rap on the Venus processing engine kept me at bay. Ricoh GRD had an attraction--I always used only primes with my Nikons--but for a do-it-all camera I wanted at least a bit of flexibility in the focal length.
The GX100 appeared to be the perfect solution, so after waiting for more than three years I plunked down the equivalent of US$750 for the GX100/EVF/case kit. My photo-taking friends and family were incredulous that I'd spent that much money on an "off brand" P&S camera, when the same money would buy a DSLR body that could be used with all my existing Nikon glass...
But for about four smug and self-satisfied months, I thoroughly enjoyed the little GX100. The virtues cited by Grafi are real, and the camera really is a pleasure to use, other than the annoying lens cap design and the disconcerting wobbliness of the lens, which always seemed anomalous on a device of otherwise exemplary build quality. (I'm aware of all the justifications for this as being part of the "floating lens" design of the camera - sorry, I don't buy it, I'm coming from the school of thought that says that the lens should remain in fixed register to the film/sensor plane at all times.)
Then I fell victim to the "black spot" problem you will easily find for yourself in this forum and in the other Ricoh forum. When you start looking around for this problem, you'll be surprised at how many people have experienced it. It seems to be related to dust on the sensor, but it is apparently occuring with the GX100 at a much higher frequency than other P&S cameras. I say "apparently", because I have been unsuccessful in tracking down hard comparative data on this problem.
My GX100 has now been in the shop twice (it is still there) for a total of 7 weeks. If I ever get a functional camera back, it will be sold off for whatever I can get for it and I'll slink back either to the waiting game that I'm recommending to the original poster, or go back in time to the Olympus 7070 or 8080.
I belatedly concur with Marceloh that there's nothing currently on the market that provides good value in this niche. While the GX100 is pretty portable, has pretty good image quality (probably would have been better with few pixels on the sensor), and aces the wide-angle requirement...it is too delicate, at too high a price point.
If you have enough money to not care about the life-span of your investment, or have enough cameras to use others while your GX100 is in the shop, the camera itself is a delight to use, and you will like the photos you get with it. If you feel like the high purchase price of something like this should carry with it a fair expectation of robustness and reliability, my impression is that the odds are against you with the GX100. And since the GX100 is, according to my criteria, the "best of breed" in this currently narrow niche, either wait, or consider that you are buying a very expensive potentially disposable camera. Since Ricoh does not even market itself in some major markets, and is not generally recognized even by photo enthusiasts as a "camera company", you should not expect to get much of a return back on your investment, even if you acquire yours at several hundred less than I paid for mine.
The good news is that the GX100 is VERY CLOSE to a bulls-eye, though I don't think there is a huge buyer market for a camera of this type. The mass market snap-shooter is being beguiled by ridiculous megapixel numbers and 18x zoom lenses. If any maker--ideally one of the top-tier ones--cares to build on the GX100 lessons, there's a really good camera not too far over the horizon...
In the meantime, make sure you have SOMETHING and have fun with it. You'll be so pleased to see yourself and your family and your friends and the places you went in the rear-view mirror of time, you'll be much less demanding about the image quality than you are now...
:-D
S.
