I've no experience with the Loxia 35, but I did originally have a look at the Loxia 50 when it was first released. In brief, the lens was sharper corner to corner than the a pre-ASPH 50mm Summicron, but the Summicron resolved better in the centre. Resolution-wise nothing to get excited about and, IMO, a poor trade-off
The uptake on the Loxias has been more from the 'motion' crowd who value the click-less aperture controls rather than the resolution and rendition demands of the stills photographer. I just hope they expand the Batis range to include a 35. Up to now I still think that apart from a manual Zeiss zf.2 wide there's nothing that beats the Sony 35/2.8 - yet. Also, not often mentioned, but the Sony (non-zeiss) 28/2 is a much better lens than it's given credit for.
But, regrettably, I agree - nothing to touch a Leica Elmar-M 24mm f/3.8.