I personally would say the album is superb, however I feel that the die hard In Flames fans who favour The Jester Race album over all the others, and especially those who don't like Clayman will find it hard to enjoy Reroute To Remain. I'd agree with the above in saying that it is pretty much the same In Flames we all love, and it's not groundbreaking new music. It's shades of most of the older In Flames albums, with progressions of ideas previously shown.
It's fair to say that the album definitely reeks of Clayman, given the fact that Reroute to Remain contains the riffing that In Flames are reknowned for, but it also contains aspects of In Flames that were kept fairly subtle, such as Ander's vocal talent (or lack thereof). Yes, Anders sings cleanly on pretty much every song, and it does at times sound fairly dire. Other than that, the 'singalong' or 'catchy' chorus, first seen in Pinball Map from the Clayman album has been expanded and worked into every song on the new album.
Sticklers for flawless music will notice the terrible production of the album, and it should be noted that this is far from "Colony" standard of production, and the sound can be muddy, and amateurish at times.
Despite of all these flaws, the overall sound is definitely catchy, and given a chance, should be enjoyed by most.