I use the same lens hood on my 35/2.8 and on my RX1RII. I'm sure it's not as "good" as the native lens hoods, but I really don't like longer than necessary lenses and I've had good success with these inverted ones. Makes inserting/retrieving the camera with the lens on easier too by kind of stream lining the front of the lens. Just need to get a 31mm (can't remember the exact size) lens cap for the domed hood.
So far my only handling complaints are the de-click switch - why does this need to be a switch on the barrel? I've already accidentally changed it to de-click when taking the lens on and off a couple of times because that's exactly where you grab it AND is has much more knurling on it than the AF/MF switch which is not nearly as easy to accidentally change. This should have been like other lenses where you need to use a tool or something like that. Don't know of any significant use case where you want to constantly switch back and forth between clicked and clickless aperture. I'll likely tap over it with gaffers tape.
I do like the sticky-ness of the aperture ring, especially in A mode as it seems. At least when brand new you won't be accidentally changing the aperture setting because it's too loose. We'll see if the aperture ring loosens up with age.
So far it's a keeper (checking on the centering still) and will probably go on the next vacation or outing in the mountains.
- J
EDIT: Added some quick conversions below. Surprisingly sharp at MFD. No major faults other than maybe ghosting and flare, which I will further test out.