OK, one more time.  How many rinses does this thing provide?

How does it compare to a KDS 22 for noise level?

Even though it's priced on the high side, this machine is located in a very upscale area and probably hasn't had a hard life -- including the water it used, which I'm pretty sure is off the Hetch Hetchy system which provides some of, if not the highest quality municipal water in the nation. 

I've e-mailed the seller.

Thanks for the replies. 

My current ISE Classic Supreme, which I think is a series 22 clone, sounds pretty much the same as Chach's KDS-21, including the trademark whine, which I think has become louder on my machine recently.

I did remove the flow restrictor on the ISE and it didn't change things enough to get much of a "rinse" out of the purge process,  but the purge does seem to effectively flush out suds residue, etc.  I have no issue with using rinse aid.  It hasn't presented any problems with the finished product from the ISE.

I guess my follow-up question would be:  What, if any performance differences are there between the Superba models, which have the heating element in the sump, and the lesser models in the 21 series (and my ISE) that have the element above the tub bottom?