The details seem pretty sparse. For example, who are the "participating retailers"? The link on the official page takes you to GameStop (ick!), but there main GH5 page also lists Amazon, Best Buy, etc. Do they also qualifty? Some retailers aren't represented at all, like Target. What about them?
There are a small number of fantastic tracks on each title, but overall I'm not too impressed with the setlists. But for $60 for the pair of them, and ability (at least on GH5) to import the GH:WT setlist and most DLC, it might be worth it.