DREAM THEATER is obviously a band, that almost everybody in the fields of hard and heavy music is aware of. You may like them or not but it almost certain that you have heard of them even if you haven't heard a note of the zillion they have played throughout all these years. Their musicianship is self evident so maybe one can only characterise and try to judge only their compositions - that's for sure.
I think that on the whole  Systematic Chaos  is more improved, sophisticated, and contains better compositions compared to  Octavarium  - it also has a strong heavy metal feeling from time to time, yet not that much metal attitude like their Train of Thought album had. It is obvious that if you are into DREAM THEATER's music this album will definitely much your taste as it contains all the necessary elements that made them the mega prog-monster band they are.
I think that the band had this time tries to concentrate more into melodic vocals plus some mysterious wickedness anthemed overall by steady, pounding, heavy riffs and rhythm on the whole. Maybe some parts of some songs tend to be boring here and there but on the whole if you like their music this album definitely appeals to you and all of their previous musical history. Many nice melodies, heavy attitude from time to time plus the 5.1 recording sounds superb. There are a couple of ballads too plus an unusual song with rapping type of vocals. Maybe there is not much more to be said about this album here. In general it's a typical DREAM THEATER album, which their dedicated fans will definitely adore - while it may also attract some others who are not that much into that style of music. It is somehow another DREAM THEATER masterpiece for their type of music.
You should also know that DREAM THEATER's new album Systematic Chaos will be released in two formats: a regular edition CD and a special edition CD and DVD. The special edition DVD includes the entire album mixed in 5.1 surround sound plus a documentary called Chaos in Progress - The Making of Systematic Chaos which last for about 90 minutes and was directed by Mike Portnoy himself. Additionally the band has also shot a video for the first single, the song Constant Motion. Some of the best moments of this album are,  Constant Motion ,  The Dark Eternal Night  and  Repentance  just to name a few. The mark here rates from 3.5 to 4 but in order to be more strict - like their playing is - here is a ...