the C4 was a big change... the C5 was a big change (I loved that rear). The C6 was YAWN. The C7 is another big change.
The C6 was made smaller to appeal to Europeans. The C6 cost less to manufacture than the C5. They will be doing the same thing for the new Camaro. Smaller cheaper. I can't blame GM if it makes $$$$, but I prefer larger cars myself.