15mm costs around $600. 14mm 2.5 about $300. That's what each lens costs brand new at the time of writing. I like the pancake-y-ness of the 14mm, but like the speed of the 15mm. However, I wonder if it's worth the extra $300. People who have had owned one or both of them, how do you think one compares to the other? Not just in terms of optical performance, but in terms of ease of use and the 'fun' factor (or something like that). If I get the 15mm, it's not coming off of my camera forever. Now, if I do go with the 14mm, I could get the 20mm and I'd have a two-lens kit for the price of the 15mm. I probably won't shoot much with the 20mm though. I'm partial to shorter focal lengths as I mostly shoot street stuff, but I think the 20 is a nice change from time to time if I get bored.