Jim, Evil Dead is much more serious, but you must realize it is quite crude by comparison. They had a single camera, no money and no professional crew. If you didn't like Evil Dead 2 I don't really think you will dig the original.
Hopefully you rented them.
Me, I love the Evil Dead films, with 2 being my fave. Bruce was superb and gave a truly one of a kind performance that should have gotten him an Oscar nod. Don't laugh! What he did in that film is insane and few actors could have pulled it off.
The original is kind of slow and dated at this point, but still is fun. Army Of Darkness is a hoot, particularly the director's cut.