Been listening and overall yes, THEY ARE DOING IT!
I'm placing it under The Red because it hasn't been a relentless 100% unmitigated pleasure as that was, but they are showing self-aware restraint yet not becoming a bore. X is one of the top 5 tracks of the year. I understand what Glitter is doing even though it isn't quite my thing, so I actually like it more than the song right after it, which is a bit too conventional/unambitious.
Other than that, my only real critique of the first half is Amber's rap on Diamond being more her standard level after she already upped her game on 4 Walls. But now I just got to a track with a Zico intro and that is SEVERELY disappointing after Diamond was such an assertively f(x)y track that demands you fall in line with their style rather than sacrifice anything of themselves.
I might be getting too meta in my interpretation there, but it is how Diamond felt and I liked that about it a lot and this Zico feature strikes like an attempt to immediately go back on what was done there. Taking the pause to vent this immediate reactive feeling may be the necessary step back and deep breath needed to judge the track fairly. Okay, going back in now.
Edit: Alright, Traveler didn't need Zico and didn't survive him taking a dump on it after pulling the rug out from under it. Sadness. But I'll leave out my meta-analysis from the final verdict on the song. Fortunately Papi was a big, wonderful surprise right after it, also containing Amber's best performance ever. The remaining tracks did well, being very f(x) although not holding as many surprises. I'll probably place the album under Married to the Music, but between this, that, and The Red, SM is out of their minds this year. What a dominant collection.