Well, after procrastinating for about four months I finally took the MPLS exam today and scored a 914.
I found the sims to be quite fun. Interestingly I did pretty poorly on the MPLS Fundementals section and very well on everything else. How does that work? I don't know what this MPLS thing is, but I can configure and troubleshoot it no problem?

My resources were MPLS Fundamentals, MPLS and VPN Architectures Vol. I (I have Vol II but found it wasn't necessary), and ElementK's Implementing Cisco MPLS online course. I found little use for MPLS and VPN Architectures since it is somewhat old and talks mainly about TDP, MPLS Fundamentals had just about everything I needed to know.
A tip for prospective 642-611 takers, find the course outline for the Implementing Cisco MPLS 2.2 course and supplement the exam objectives with the topics on the course outline, the official exam objectives seem to be out of date.
I'm happy to have finished my CCIP today as I'm starting at WGU next week and didn't want to continue to put off the MPLS exam.