Late to the party here - but for anyone who is having issues with Eagle shifting performance, look at replacing cables & housing! I had similar issues despite multiple attempts at adjustment, including B-screw etc. Many trips back to the LBS as well with no better results. Eventually I replaced the stock cable & housing with the JagWire Elite Link and suddenly it all worked perfectly. This is an extremely low friction cabling system with almost no compression in the housing. (There are other low friction options though, but this worked great for me.) Crispest shifting ever! After a year its still all working just as well as when first fitted.
The issue with shift performance was definitely friction. Seems manufacturers will use very low quality cables & housing, even in their top level bikes. Who ever asks what type of cable & housing is used, as part of a buying decision?? Cost savings for large volume manufacturers would be significant by skimping here. Anyway, try it if you have problems. It was like night & day for me!!