Is the extended any good? I've only seen the theatrical and been meaning to revisit it.
The extended edition isn't really good, watch the theatrical cut first.
The extended cut is only worth seeing as an "extra" for the many extended scenes that could have made it in the theatrical cut had the studios not insisted on keeping the film shorter. Other than that, it's a bit messy. The beautiful close-up of Virginia Madsen as Princess Irulan at the beginning was replaced by a slideshow of paintings and a male narrator. Some violent scenes were edited out and some effect shots are shown twice.