Can't speak for the 13.3" retina, but I recently upgrade from a 2010 13.3" MBP to a 15" retina. The retina was a bonus from a client for finishing a big projec

Can't speak for the 13.3" retina, but I recently upgrade from a 2010 13.3" MBP to a 15" retina. The retina was a bonus from a client for finishing a big project ahead of schedule. The speed was the major selling point for me. In fact I almost didn't want the screen, but since it was free I went ahead and got it. The speed is incredible compared to a spinning HD, but the screen is simply amazing. I look at my old MBP and the screen is harder to read. The strain on my eyes has been reduced as I get far fewer headaches with the new screen. TLDR; Going from a spinning HD to SSD is worth it. Once you have the screen you will wonder how you dealt without it, but I still wouldn't pay that premium out of my own pocket.