I'm curious why an s95 or s100 isn't in your list? What you're describing is pretty much exactly what the camera is for - same sensor as the g12, f2.0 lens (at wide angle)...
I still want things like RAW, manual controls, and Aperture Mode but don't care about lots of extra features. Just a light weight camera with high quality results I can easily carry in my hand or pocket (albeit a big pocket).
...yes, yes, and yes (though aperture priority mode is not terribly useful on a compact because all apertures have nearly the same depth of field on a smaller sensor for most practical purposes) on the s95/s100 as well.
I thought the Canon G12 was the answer but I'm now confused by all the various models and options for the 4/3rd format. My budget is $500, so Nikon's new V1 and some of the higher end Panasonic and Olympus models are out. I don't need to go over the top with interchangeable lens - I'll take the D3s when I need that - just want high quality vacation shots.
(moved this part)
I'm a happy Nikon shooter with my D3s and assorted lens, if I want to point and shoot I pull out my iPhone. However I'm looking for a camera for those travel and vacation days when I don't want to lug around the big stuff.
I assume that you're considered just buying one of the entry level Nikon dslr models and using just one cheaper/lighter lens on that?
There's a few reasons not to get m43rds -
1. You just end up with another system that needs extra lenses.
2. If you're carrying more than one lens it's hardly portable anyways.
3. They do have a prime low light lens, and a short zoom lens that make m43rds "big pocket pocketable", and this is an older pic, but with any sort of longer zoom lens m43rds is not in any way pocketable -
4. With the older sensors, a m43rds camera with a zoom lens will give you worse low light performance than the best compacts (the ones with an f2.0 or f1.8 lens, like the s95/s100, lx5, or xz-1). This may have changed with the newer panasonic sensors, but those are only in the very new Panasonic gx1 (not the Olympus models, or the older Panasonic models). I mean in the very small m43rds size - the larger Panasonic g3 has the newer sensor to, but it's bigger and pricier.
If you just carry a m43rds with their f1.7 prime lens (can't zoom) that can be worth it.
I break it down like this -
1. If you can live without zoom and want low light performance, an older model m43rds with the f1.7 pancake lens would give you the best low light performance for relatively cheap...thought the f1.7 lens is $350 itself, so I don't know if it's in your price range. There are other non-zooming options that will give you better low light performance in a similar size, but they're noteably more expensive - the Fuji x100 fits a dslr sensor an f2.0 lens in the same sized package but it costs $1200. The Samsung nx200 is my favorite, has an f2.0 pancake lens, but would also cost around $1200 altogether.
2. If you do need zoom, my favorite g12-sized camera on paper (I don't own one), if you're willing to run your shots through a raw converter, is the Olympus xz-1. It has a great lens on it - sharp, even in the corners according to test shots and reviews - something other compacts and most cheaper dslr lenses don't have. And it's aperture values for low light are - amazing, f2.5 at the far end of the zoom. (Though note that the best compacts even at the best settings are ok but not fantastic in low light.)
3. However...I don't own any of these.
I own a Canon s100.
Because everything else is to big. The s100 is small enough to fit in a jeans pocket and carry around all night like that (granted, it takes up the entire pocket, but I carry mine pretty much 24/7). It has the same sized larger than average sensor as the xz-1/g12/etc (the s95 has exactly the same sensor as the g12).
It also has an f2.0 lens (at wide angle), shoot raw, full manual controls, etc etc etc.
It's currently the quintessential "dslr compliment" camera because of all these factors, and it's size. It's image quality is the basically the same as the larger compacts (some of them may have slightly sharper lenses, or better corners, but overall the differences are tiny). Your d3s is a big, big camera, so this might not be true for you, but a lot of times people have come back and said once they bought an s95/s100 they found they never really used their larger "compacts" like their g12 any more - if they wanted something portable they grabbed their s95/s100, if they wanted better quality they grabbed their dslr with a single lens...owning an s95/s100 they found their was no situation where their g12-sized camera's degree of portability was useful. Now not 100% of people agree with this, but a ton of people did come back and say they found this to be the case.
. Still want to at least be somewhat loyal and check out Nikon 7100 as well.