it's a 35mm leaf shutter camera, IBIS, to my mind is is last on my list of priorities.
i've been using the rx1 for two years and have done a great deal of work with it.
as a previous poster said, i think a 42mp sensor is a bit of overkill, i may control the urge to upgrade as i really, really like the rx1, i'd go as far as to say its the best camera i've had, with the hasselbled swc coming in close second and ebony SU 4x5 with schnieder 80mm xl third (both long gone.) the leica m6 too.
if it had a 50mm version i'd be in 7th heaven...