A little creative ms-painting to overlay the 30/1.4 and 50/1.4 MTF charts:
Despite the lower MTF in the center, I think the 50/1.4 is a lot more lens. To be honest I'd like to try the 50/1.4. I might try it later this year or early next year.
More likely though, I might sit tight until Nikon ships a new 50 and decide. Maybe we’ll see a Nano-coated f/1.2 AF-S come out. I’m betting we will - that'll be an interesting day.