I have driven the FX37 4x4 and was really impressed, it has a good lot of poke and is a very comfortable and stable drive, the interior is well made with stitched leather dash and i like the internal lighting, not a fuel hungry as you woudl expect a 3.7 petrol 4x4 and i was getting well over 30mpg out of it.
I know this is not the one you are thinking of getting but the FX37 did give me an all round good impression of Infinity.