Olympus Zuiko 17mm vs Panasonic Lumix 20mm

Among the always-on lenses I would consider (14 mm, 17 mm, 20 mm, 25 mm) one could roughly assign:

- 14 mm f/2.5, most compact, optically ok but last in this pack, slowest lens

- 25 mm f/1.4, fastest, probably best optically, largest lens

- 17 mm f/1.8, fast-ish lens, maybe second-best optically, second largest lens

- 20 mm f/1.7, fast-ish lens, optically still pretty close to the best of this set, still pretty compact

Unsurprisingly, the f/1.7 and f/1.8 lenses are the compromise lenses, balancing speed, size and IQ. But the 20 mm seems to me the most bang-for-the back compromise, being pretty close to the best in all three categories (though one could argue about what pretty close means).

Full disclosure, I have a 20 mm and have a 14 mm on order. I really want/need one really compact lens. Don't mind the size of supplementary lenses too much (I own the 7-14 mm) but I really want one lens that gives a compact package together with the camera. If somebody brings out a f/1.2 lens (or f/1) that is optically ok (like the 25 mm f/1.4 at f/1.4) wide open and has AF, I will most likely get it.