Some great work. The Kobe render was superb. The only thing I would critique is that the skin on both models appears a little plastic and dry, which is quite evident on the ears.
Also this new characters looks quite similar to your Kobe model. It seems the same model was re-used and the low resoltuion was just tweaked to change the shape. Perhaps he needs a little more low frequency changes. And maybe a little more depth to the skin scatter.
Super model and great tips. Also your previous celebrity models are awesome, great likeness.