I realise that half of you that post in here do have TOB so i might as well just ask it here anyway.

When TOB is installed does it add on to the SOA campaign or add a completely different map of juicy goodness.

I LIKE PIE!

A completely different map of juicy goodness. There is one exception - you can access a multi-level dungeon from both SoA and ToB. Otherwise you have to complete SoA or start a fresh ToB game to access the new Throne of Bhaal map.

Exactly as shamrock_uk said.

Note that there is one additional "add-in"- the XP cap for the whole game is now 8 million per character (or level 40, whichever comes sooner). This can make the later part of SoA slightly easier, since it's quite possible to hit the XP cap for SoA before finishing.

kk thanx for that

TOB could almost be called BG3 if it was longer.

A lot longer!