I was just browsing through the Dream Theater statistics in Setlist.fm. Here's something interesting (to me at least):
So far, The Astonishing songs account for 580 plays (20 shows x 29 songs - the NOMACs tracks are not counted). That's more plays than the songs in Dream Theater and BC&SL.
By the time the European leg of the tour ends next week, there will have been 783 plays, which will make The Astonishing the 8th most played album by the band.
If you add the 21 shows of the North American leg in April/May (well, I see 21 shows listed on the official website), the total plays rise to 1392, making the album the 5th most played, surpassing SDoIT.
And that's only in 3 months of touring! By the end of the North American leg, the band will have played 48 shows, which is basically half of a world tour. So, we can assume that the total plays for The Astonishing will be 2000+ by the end of the year. That would make the album rise to 4th place (surpassing FII).
Now, I'm assuming the possibility that future shows will replace some songs with earlier classics. If that's not the case, and considering that they will surely play at least some other 48 shows (they've confirmed the tour going into 2017), the total ammount of plays for the album will have made it almost 2800, making The Astonishing the 2nd most played album (surpassing Awake and SFaM, and only behind Images & Words).
That is astonishing!
(Yes, the last part is possible, but unlikely. Still, in May, The Astonishing will rank 5th, becoming their most played album besides their '90s material - and that in less than 4 moths after release. That's pretty mindblowing if you ask me. I think it shows the band doesn't rest on their laurels and are really confident and happy about their new music).
EDIT: For reference, here are the Top 5 albums ordered by the ammount of plays the songs have received over the years. The statistics in Setlist.fm might be incomplete, though. Either way, The Astonishing will rank somewhere in the Top 3 once this World Tour finishes. Calling it now.
1st: I&W - 3615
2nd: SFaM - 2703
3rd: Awake - 2446
4th: FII - 1547
5th: SDoIT - 1372