As hef said, a lot of the depth comes from the lyrics. So many of their lyrics since (I'd say most of them) are very in your face, blatant, etc. In other words, it is pretty obvious what they are taking about. Not that there is anything wrong with that, but just like I like movies or shows that make you think, the lyrics on many of the songs on Awake were thinkers. To this day, people still debate what this song or that song from the record is about. And digging into the lyrics and trying to decipher what they mean while listening to the song at the same time can take you on a journey that adds layers of enjoyment to the song that maybe you don't get from listening to a song with straight forward lyrics that don't make you think at all.
Lyrics I think have been good since SDOIT:
Endless Sacrifice
Vacant
These Walls
I Walk Beside You
Panic Attack (Yeah, really)
Forsaken
The Ministry Of Lost Souls
Wither
Actually, those are just some of the ones that pop right out at me as being less direct and in-your-face-blatant as far as subject matter. Other than the majority of lyrics found on
Systematic Chaos, much of the lyrics' subject matter in recent albums have been either sad/depressing, or angry, and in a less poetic way than songs from earlier in their career.
There are probably less "enigmatic" things to write about, songs like "Voices" or "Trial Of Tears" or "Misunderstood", that are poetically ambiguous yet still intriguing. Or perhaps JP's "Wither" is a testament to how hard writing has become, and that perhaps the subject matter in his younger years in DT was just easier to concieve and develope than now? Perhaps that's something that Mike was also feeling needed a recharge in the band - lyrical subject matter. But I think if the next album's lyrics are still a bit direct, or perhaps even pedestrian and less poetic, then we can probably start to worry a bit more about where JP (and JLB and JM, if they write and lyrics) is going with his words.
-Marc.