Quite possibly because of my age, and when I developed an appreciation for music, I don't hate Charlie's vocals as much as many other people do. I still think that JLB is the superior vocalist, but Charlie did a great job on that album, in my opinion. Someone mentioned "hairspray vocals", but I don't think that applies to him anymore than it could JLB. Winter Rose, high octave range ect. ect...
For me there are some absolutely stellar songs on that album. I personally enjoy it more than the last four albums combined. Then again, I've almost completely lost touch with anything that the band has done in recent years. The last album that I enjoyed was SC.