Revisionist history by Tommy Shaw and James Young, who act like they wanted to rock, as if they are Black Sabbath or something, while DDY wanted all ballads. Shaw wrote Sing for the Day, and Shaw and Young were the ones who insisted that Babe be a Styx song; DDY had written it just for his wife, and the others insisted on recording it as a Styx song because they knew it'd be a hit. I am a big fan of both Tommy and DDY, so I do not really take sides, but Tommy (and Young, who is as about as lucky as anybody) has changed the story too many times for me to buy it. DDY was a pain in the ###, but results are what matter, and the band was at their best and did well when he was steering the ship. Adding Tommy gave them a 2nd great songwriter.
That aside, The Grand Illusion and Pieces of Eight are both terrific records. Both are great from start to finish.