Hi Joel,
I hope to get both modules for long-term test sometime later when the initial buying madness will get over

Form what I heard, there is huge demand for GXR. And so there is not enough number of sample cameras.
GXR+A12 fits nicely in my palm. Probably even better than GRD+GW lens. Most probably because of size of GXR grip. The size is very well balanced and I can hide the camera in my autumn coat. Of course, without EVF. But it's definitely pocketable and without making the pocket too bulky and noticeable.
True, the A12 AF speed is on the slow side. But again, I'm quite sure it's mainly because of the Macro nature of A12 lens. Ricoh already proved (with CX1/2 and GRDIII) that they can do pretty fast contrast detection based AF. So all they need to do is to release another APSC based (non-macro) module. I'm quite sure this new module will be very fast AF performer.
But even despite slower AF and in my opinion somewhat underpowered speed of RAW continuous mode, A12 is a dream camera! If properly focused and exposed and with some fine tuning of JPEG settings, there is no problem using all ISO values and even without the need to go to RAW. I'm a RAW freak, but I like what I see in A12 JPEG. I will most probably still use RAW. But I would not mind to switch to JPEG in case of low space on SD card.
On the other hand, I would not recommend A12 to people used in small sensor DoF and to people who relies on Snap focus. Sadly, my trial time is almost over so I have no chance to try it side by side with GRDIII (in terms of usability to capture fast actions and scenes without the time to focus properly). But from what I saw up to now, I think the GRDIII will most probably beat A12 in this particular area. Maybe it was just my inexperience with A12 (due to short time of use), but I was unable to take a reasonable sharp photo of Lucia in movement. Something that was not problem with GRDIII and f1.9. Simply, the GRDIII DoF is often a serious advantage. But when it comes to portraits and the need to separate subject from background (and high ISO usability) there is no contest. A12 is a clear winner here.