I can give you my opinion of my friend's HAF-922 (midtower case).
1) When all three fans are on, it produces a nice, quiet, whooshing sound (to me anyways) without any annoying pitches or whines. My friend even bought an extra 120mm fan to point straight at the video card. Ventilation is definitely good in this case.
2) But the open side panel and the open front panel leaks out a lot of sound. I think the loudest component for his machine is his stock Intel cooler on his Core i5, which is audible if you pay close attention to the noise coming from the computer. If you have quiet components, I'm sure it wouldn't be an issue.
3) The hard drive mechanism seems a little cheap, but I haven't been around the computer long enough to let you know if it dampens the hard drive at all.
4) I'm a big fan (no pun intended) of dust filters, and the only one in this case is so hard to reach and clean that it might actually discourage people from doing so.
Again, this is just my personal opinion. I helped him build the computer, and his only criteria was that it had to be housed in this case, so he's in love with it. It's definitely a very good case, it's just not right for me.