@Herr Wolfsheim: vielen dank. Miele was at the top of the list until I discovered how poor is their reliability.
@Snackdog: Interesting. These types of units are quite common in Europe, Japan, and in many loft conversions (not to mention the myriad walk up apartments in cities like NY, Philly, Boston, etc) where venting is disallowed by contract. It seems that the folks who report problems with knotting oft discover it is due to overloading - especially with the LG & Bosch Axxis units. We are not fans of line, or rack, hanging.
But regardless, we need something. Argh.