Michelangelo: Pieta I

Pencil drawing of a part of Michelangelo's Pietà. First piece of my Pietà series.

Used materials:
HP Bright White Inkjet paper (106+ Brightness)
KOH-I-NOOR Progresso woodless pencils HB, 2B, 4B, 6B, 8B;
KOH-I-NOOR Hardtmuth 1500 pencils 3B, 6B, 8B;
Zebra M-502 mechanical pencil, different erasers

IMPORTANT NOTE:
Please make me a present of your detailed comment, because I'm really curious about that! I'd like to improve my art skills so it's very important to know what other people think about my pictures! So may I ask you to write down what you think about it and give me any ideas why do you like/dislike it, what's your pros and contras? Thank you so much!