You may want to add the Canon 35mm f/2.0 IS to your consideration also. Dustin Abbot makes a compelling case for it here:http://dustinabbott.net/2014/03/canon-ef-35mm-f2-is-usm-review/
The folks at Lens Rentals have this to say about all three:Canon 35mm f/1.4:This is the wide angle member of the Holy Trinity of L prime lenses: the 35 f/1.4, 85 f/1.2, and 135 f/2.0. It’s one of the older designs in Canon’s lineup but still nearly flawless: sharp even in the edges, contrasty, and has smooth out-of-focus highlights. I find myself trying to find a way to frame a shot at this focal length, just so I can use this lens. If you’ve ever asked the question “why would you shoot with a prime lens when zooms are so much more convenient” this lens will demonstrate the answer for you.
However, from a pure resolution standpoint it has now been passed up by the Sigma 35mm f/1.4 lens, which is sharper both in the center and along the edges and corners. The Canon remains a bit more predictable, though, both in autofocus accuracy and bokeh.
April, 2013Sigma 35mm f/1.4A:This is the sharpest 35mm made. It costs a lot less than the Canon 35 f/1.4mm or the Zeiss 35mm lenses. Any questions? It’s extremely well built and everything I’ve been able to see, inside and out, indicates quality control has really improved at Sigma.
If you’re a bokeh fanatic, you may like something else better (or maybe not, that’s a subjective call). If you need Image Stabilization, then the 35mm f/2 IS may be worthwhile. Otherwise, this is the 35mm lens.
Arguably as good or better than anything else made, and at a lower price.
Canon 35mm f/2.0IS:A modern day update to a versatile, compact and lightweight wide-angle lens, the EF 35mm f/2 IS USM is incredibly bright and offers image stabilization, superb image quality and construction. The EF 35mm f/2 IS USM features a GMo aspherical lens element for high image quality, an 8-blade circular aperture diaphragm for soft backgrounds, a minimum focusing distance of 0.79 ft./0.24m, plus optimized lens coatings for minimized ghosting and flare.
A rear focus system, and ring-type USM with micro-stepping drive provide faster, quieter, and more precise autofocus performance perfect for video. It has a 4-stop Image Stabilizer system that detects panning and automatically switches to the optimal IS mode.
I'm not sure what you mean by "unkillable," but my Sigma 35 has the feeling of a well put-together Swiss watch. It is not weather-sealed if that matters.
By the way, you've got a nice bunch of pictures on your flickr site.