Highly recomend Miele S5981. I bought from Johnson Company at $8980 1-2 years ago. They came to my place to do a demo, and there were so much dustmites on our bed!!!!
Later found that it is only selling at $6xxx http://www.allercure.com/eindex.htm
so check the price around.
My girl have allergic rhinitis, it did help a bit.
She is very allergic to dustmites.
But if you are allergic to Dustmite, i recommend Anti-dustmite beddings. Improve 85%-90% my girls problem