Conversation so far:
What kind of vocal style does Sakis Rouvas have?
His voice is best-suited to power ballads, his signature style due to his sensual tone.
What criticisms did Sakis Rouvas receive?
Rouvas' detractors have criticized his voice as average, or limited, contending that his appeal is based on image

Question: What other criticisms are there?
Self-contained rewrite: What other criticisms are there?