Prep for written - From CCIE R&S -> CCIE SP.

Hello All, 

I am starting on the SP journey after passing my CCIE R&S on November 5th.

I had some questions about resources and I wanted to get some feedback aswel as an idea of how much of a gap there is.

For the most part, this is an MPLS exam from what I can see.

I have booked the written exam and I am currently reading the following books: 

*MPLS and VPN Architectures

*MPLS Fundamentals

*Developing IP Multicast Networks

*Interdomain Multicast Routing (Great book!) 

Are there any further suggestions that I can read here?

I was thinking about supplementing this with the SP Advanced Tech class but I'm not sure if its too early to get into that (for the written).

I'd be interested to hear other peoples experiences going from R&S -> SP.

All the best, 

S