What you can do to improve performance in the short term is throw a handful of cotton or sheet cotton, the kind you buy in the First Aid section of drug stores, into the Polaris's catch-bag. Much of the stuff that passes through the bag will get caught in the cotton, improving cleaning.

I used to use a Polaris 165--bigger version of the 65-- and that really helped.

(may be using it again as my Blue Diamond has to go to the shop).