13" Retina Macbook Pro... Worth it?

I currently own a 2011 Macbook Air (Core i7, 4GB ram, 256gb SSD) and I just can't decide whether buying the new Retina Macbook Pro is worth it or not.

A lot of people are saying that the new 13" Retina MBP, without discrete graphics, just isn't worth it for $1699.

Whether this is a downgrade or not is a huge concern for me. I would die for a hi-res computer that has a more solid build and faster processor, but is it worth the ~$400-600 it will cost me to upgrade? I do web development and a fair amount of editing in CS6.

What are your opinions on the new 13" RMBP?