I have the Sigma and the 50mm. Sigma is a great, sharp, cheap lens with reasonably fast AF. However the color, while good, isn't as good (to my eyes) as the 50. To me, Sigma tends to produce colors that are a bit on the blue / colder side. Same goes for the 19. This is not a fault, but rather the characteristic of this lens. The difference is most visible on the inside. On the outside, especially in bright light, the 50 has very different colors than on the inside. In bright light, it's just another sharp prime. But there's an amazing transformation when using 50 in subdued (not poor) light, especially when there's lots of color around. It just renders everything beautifully crisp with very rich, vibrant but not oversaturated colors. The big bummer however is the AF speed, especially in dim light. So, if you have experience with all three lenses, where do you think the 35/1.8 fits in ? Optically, is it close to / same as 50 ? How does it render colors ? And how fast is the AF ? It's hard for me to justify getting 35 vs 30 - there's a huge difference in price (especially since I got 30 as a part of the 2 lenses for $200 deal at B&H), the 30 is a great lens in it's own right, and 35 is getting a bit too long, I'd rather have 28... but if it gives me all the sharpness and color rendering of 50, with faster AF in low light, and with better bokeh than 30, plus OSS... it may be worth it.