Hi,
Just bought and installed one of these (Hoshizaki C-100BAF, about $2700 with the drain pump, vivco-ice.com, salesman was John S - they are very helpful, I asked questions for over a year and they were always patient). The ice is amazing. It is a little louder than I expected, but still a little quieter than a regular mid-priced dishwasher and it doesn't make any noise when it's full and not making ice. I think you do not need a drain pump if you can drain via gravity (I installed mine in a bar area that had a sink - so I needed the pump).

Overall, we are very happy with it (but do wish it was a little quieter).

Hope this helps,
Mnovas

See my comments in the thread below.

Basically, ice machines as a group aren't very quiet, at least the real ones that make clear ice that doesn't bunch together and requires a drain, as opposed to those that are glorified refrigerator icemakers in a separate appliance and make cloudy-white ice crescents.

Here is a link that might be useful: ice machine thread