Well it would be mighty hard to screw up a decades channels. The thing that killed them on the Sirius side was they were too shallow (repetitive) and only played the top hits. Where as on the XM side they played wider variety going deeper into the top 40 hits and then throwing in some that weren't in the top 40, but maybe in the top 100 for variety sakes.
I like the fact that they will be adding Rick Dees, Casey Kasem, The Cous and apparently many others across the decades channels.
I have never really been a fan of the Hits From Hell that the 70s always did, because I often found many of those hits were great tunes and after hearing the DJ slam the song as this terrible hit, was a huge turn off for me. I always like XM's approach much better and I certainly hope that is the philosophy they go with on all the decades channels going forward.
I like Sirius names for the channels, but content if chief and '80s on 8 or '40s on 4 works just fine!