Disorganized and overworked professor causing disappoinment and headache
I don't think there's anything wrong with voicing your concerns, but if you're going to you need to find a way to do it constructively while sticking to the facts.  "Much disappointment and headache" might be entirely correct, but this is more of an emotional comment.  

Also: are there other students you can get to join you in voicing this concern?  Maybe you could all approach the problem together.