Started testing the MSO1074Z today. First thing I tried was seeing if Frame recording captured the Digital channels (it does) - and whether it could decode the Frames while playing them back (it can't). It appears you can't turn on Decode while in Frame playback - and you can't turn on Record if you have Decode turned on.
One neat feature I did discover (which I don't believe is available on the MSO2000 series) is Plot. When selected, the "change trend of the bus data will be displayed in vector mode" (as the Manual puts it):