I thought it was OK. Very silly, and very gory. Just complete over the top wackiness. I would have rathered it was more dark and brooding like the original story, but it's testament to the era in which it was made.
In the sequel, the doctor has fruit bat wings sewn on his head, and then has himself FedExed to his med student nemesis. Truly awesome silliness -- especially when the student reacts to opening the box by grimly but calmly getting a broom to whack the doctor down from the ceiling where he's fluttering about on his new bat wings.
I plan on adding Beyond Re-animator to my Netflix list. I hear Bride of Re-animator is pretty... lame. Supposedly they are expecting the release of a 4th Re-animator film due in 2010. Noticed on Amazon.com "Army of Darkness Vs. Re-Animator"... might have to order that one. Bruce Campbell is definitely my favorite B-movie actor, would love an Army of Darkness sequel. Ash is a great character. Would be weird now that Bruce is fat and gray though.