My take on the 'screams' and violent nature of the transformation is that it would be painful. As Ten said to Rose, every single cell in his body changed. That would be intensely painful. As for 'what happens' to Time Lords, I think that Ten was right on the money when he told Wilf that 'another man' goes swanning off after the regen is complete. The individual is gone, but the memories remain.
So yeah, I think that regeneration is death for all intents and purposes. The person who was The Doctor dies and someone else who shares his memories is born.
Some say that, of all the souls he has encountered in his travels, his was the most human.
know is, we've lost a legend.
Goodbye Leonard Nimoy.