Any enterprise operators very happy with their MPLS providers?

["McCall, Gabriel" <Gabriel.McCall () thyssenkrupp com>]

I'm getting ready to prepare an RFP for our next generation WAN, and would like feedback from anyone else who has 100+ 
MPLS nodes on their quality of account service and technical performance.

My current landscape includes AT&T, Sprint, and Verizon. I'm almost completely happy with Sprint- they're about in the 
A- range. AT&T is muddling along at about a C, and Verizon is a solid F. I've heard very good things from some 
CenturyLink customers and will definitely include them in the bidder list- is anyone else doing a very good job for you?

-Gabriel