I have chance to get a second hand Leica X1 in mint condition for a very rare price. Is it better than my lovely GRDIII or is it only the brand I will pay for?
X1 delivers definitely better image quality than GRDIII. The size of sensor always matters X1 will give you very comparable image quality with GXR A12 modules. If I'm not mistaken, they all share the same sensor.
You should remember that X1 is not as wide as GRDIII (35 vs. 28mm). And at this precise moment, X1 AF is pathetic. However, several reliable Internet sources say (for example here) that Leica is working on a new X1 FW, which should significantly boost the AF performance and brings some new features. So, if you can buy the X1 for a good price it's probably the best time to get it?
Thanks for the comment Pavel.
After using both GRDII and GRDIII I'm very familiar with Ricohs excellent ergonomics. Will the X1 be so fast and simple to use than GRDIII?
I'm using Nikon D3 and D2x DSLR with dedicated buttons for adjustments. With Ricohs programmable "thumbwheel" I'll reach primary functions pretty fast. I really hate to go down in menus for basic adjustments. The ergonomics are significant for me. Will I be disappointed with the ergonomics in Leica X1?
I think Leica GUI is very simple to use? And there are some dedicated controls for shutter speed/aperture and probably some others via buttons? I would suggest you to get the X1 manual and eventually check some reviews (for example this one). As much as simple is the Leica GUI, it's also free of many advanced photographic features available in GRD/GXR cameras. You should definitely check the X1 manual before the purchase!
I think the biggest disappointments will be the X1AF speed (probably fixed/improved in a near future) and LCD. X1 is equipped with with 2.7" with just 230k pixels! It's somewhat disappointing for camera of X1 grade and price level, especially considering there is no EVF to connect? Such LCD was maybe enough few years back (GRDII used it). But there are now available very nice 3" 900k pixels LCDs. Ricoh use them even in their entry level CX models. So I don't really understand why such nice LCD was not added to 2k USD camera?