Item creation is fun.
I made myself a +5 Cold Iron Warhammer with Holy (+2d6 vs evil) and Disruption (Save or die evil undead!) enchantments.
Plus a belt of giant strength +6
And Khelgar had a +3 flaming dwarven axe
Overall I wouldn't say it's time consuming, unless you either sell off gems and books... and have to get them back.
But other than weapons and armor... it's not really worth it unless you have to have one of the items that can be made since you have no control over the recipie... but weapons and armor are really customizable and well worth it.
And unless I encountered a bug, it would seem there are recipies that are NOT in the books....
...for instance I made a shield with an additional -10% spell failure rate.
<{POST_SNAPBACK}>
It looks time consuming to me. My will to complete the game over rules me having fun making weapons and such at the moment.
Items can give negative percents on spell failure. Some of the games items do that.
That war hammer would rule if it did 2D6 vs good.