I have not tried that particular guitar, but I've tried most of Seagull's guitars and I can tell you, that will be one very bright 12 string.
If their other 12 strings are any indication, it will play very well as far as the neck and action goes. That would be my guess anyways. The brightness will depend on the person who plays or buys it as to whether that's a good or not-so-good thing.
===================================== One Alvarez in the hand is worth two Taylors and a Martin in the guitar store!
The Concert Hall body has a thin upper bout, something I didn't really like about the 6-strings I tried. It may make it more comfortable to hold, but as TonyKgull, said..it will be brighter than any of the dread-bodied Seagull 12's I have played.