Sigma 20/1.4 vs Loxia 21 by Ming Thein

http://blog.mingthein.com/2015/11/23/sigma-20-art-vs-zeiss-21-loxia/

Summary:

In hindsight, I think ‘battle’ may have been the wrong term to use: it really isn’t one. What we have are two of the best wide angle lenses I’ve yet seen, period. Both have tradeoffs ut they’re sensible; there is therefore no clear winner here – you may value the 21 Loxia’s size over the Sigma’s speed, or autofocus over the ability to take filters. Or field curvature over corner resolution – etc. Despite being similar in focal length, the 21 Loxia and 20 Art are an excellent example of where lenses are clearly built for very different application profiles – and still capable of achieving the same high standard of performance. There are situations in which I strongly prefer the Loxia over the Sigma, and vice versa – fortunately, these almost never overlap. For the first time in a comparison, my choice here is actually very simple: I have reasons enough to have both. MT

What do you think? They both perform really well but for me the Loxia's size is hard to beat.