Mechanically, I prefer ToEE. I would LOVE to see this engine applied (WITH PATCHES) to other scenarios and mroe plot intensive games.
Storywise, Icewind Dale 2 was a much better involvement. As was stated, the designers jumped rings around the ToEE storyline as presented. However, I think the Temple's storyline, because it came from the old school of though where design was minimal to allow for more DM customization, was so simplistic it really doesn't have a lot of grist for the mill.
IW2 wins on style, Temple wins on execution.