Titleist 905R Vs Titleist 913 D2 D3 drivers

I am currently using the Titlest 905R Driver and have for several years. I am a low handicap player and tried the 910 series and ended up staying with the 905R, but I have decided to get fit for a 913 driver. Can you tell me the improvements and differences in the new 913 line vs the 905r. 

Thank You

John G

There are improvements to the heads, weightig and faces to improive forgiveness and spin, as well as the adjustability features, and being able to get fit into correct shaft and loft and lie angle settings.