You can import SoD saved games, however not all items will transfer over. There are about 10 or so items that can be transferred, and they will not be on your characters when you start the game (due to how the story of BG2 goes), but will appear in certain places around the world (monsters and containers). These items will only appear there if you transferred them, with the exception of the Shaman-specific items which will always appear.
For a list of which items can be transferred, there's various threads on the topic here on the forums already.
I hope Beamdog will eventually allow items in Bags of Holdings to count and be transferred.
The problem is that would require all the SoD items to actually be in the BG2 data files, which would bloat the already huge number of items in there. Not worth the effort, considering very few items from SoD can compete in the higher-level world of BG2 (though some certainly can).
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For a list of which items can be transferred, there's various threads on the topic here on the forums already.