Icewind is much more linear indeed. I've played it without ever having to wonder where I should go next. As far as I could tell there were no optional quests or map areas, but it was enjoyable. The fighting is quite important, as is the storyline, but Icewind Dale also has some interesting magic items. If you already have the game, it would be a shame not to play it
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The last arrow of Legolas kindled in the air as it flew,
and plunged burning into the heart of a great wolf-chieftain.
All the others fled. -J.R.R. Tolkien, The Lord of the Rings