In reply to:
What is the difference?
In general;
Full = LLU ADSL equipment + LLU voice equipment
Shared = LLU ADSL equipment + BT voice equipment
As Sky use BTw voice services (for Sky Talk line rental & calls), but have their own ADSL equipment, they're shared in the same way BE/O2 are (who don't offer line rental or a calls package).
Talk-Talk are an example of full unbundling.
Ade
ADSL2+ with BE
DL Sync Blimey....4707kbps now!
UL Sync 1088kbps