Took some test shots at about midnight outside my window at 0030hrs! With an A7 + 35f1.4FE, M35FLE and M35f2ASPH. Had a quick glance at the shots and some immediate conclusions - no pics - still trying to figure out the best way to post the comparisons.
Sony Zeiss 35f1.4 FE and M35FLE - both with filters as too lazy to remove them
f1.4 - both lenses have obvious smearing at the edges, the Sony a bit better than the FLE, but overall the FLE looks sharper and cleaner
f2.8 - smearing on both reduced to about the same degree but but still obvious on both, the FLE still looks a bit sharper
f5.6 - edge smearing almost gone on both, some flare but not too noticeable, with the FLE being a little more obvious
f8 - almost no noticeable smearing for both, flare characteristics both similar with Sony a wee bit better
M35f2ASPH - without filter
Edge smearing is a little bit worse compared to both 35f1.4 but the flare is a bit more obvious
Some quick conclusions:
The Sony is a wee bit better on edge smearing and flare control than the FLE but the FLE looks cleaner and a bit sharper. The softness on the Sony, the Zeiss character? Personally still prefer the FLE look but the Sony is so close and better in some ways.
Both 1.4s are overall a bit better than the f2ASPH and visibly better in control of flare.
The 2 Leicas are some of the best 35mm lenses ever. Now there is a 3rd one, the Sony.
I am using mirrorless so that I can walk around with an A7 and 3 lenses in a pouch, not a backpack. Size, weight and IQ are the main considerations. Obviously the M lenses are not at optimal unless on the M bodies. But the interesting part is that now IQ from a Sony A7+FE35f1.4 is almost similar to a M240+35FLE but at 1/3 the price, that is real interesting.
My only real gripe is the size of the Sony. It is as large as 2-3 RF lenses. I don't know whether I can 'adjust' to this 'bigness' but the IQ is just amazing. But remember, these are only first impressions, after 2 hrs with the lens.
I'll try to post some shots the next few days. But this Sony-Zeiss, Made in Thailand is a real eye opener.