I had a buyer in June whose positive feedback stated "Thanks, as described" and then gave low DSR for item as described without explanation.

I've decided I'm not going to worry about the DSR system.  There's too much randomness about it..... so it's fruitless worry about something you can't control.   My listings are super-thorough, and the pics as clear as anyone's mostly - I honestly don't think I'm capable of doing much better.   And it is a bit reassuring I guess, that if it's happening to me and other honest sellers, then it's happening to everyone.  (I know that sounds arrogant but my feedback speaks for me!) 

So if sellers like us can't protect ourselves against low DSR's then I can't worry about it.  I'm thinking of adding a line to my listing template that alerts buyers that low DSR scores aren't anonymous and maybe if we all confront buyers to explain the score given we can slowly educate them.  

Anyway, even if I lose my top-rated status, I'm not sure I care.  Buyers can't find the badge easily as it's not on the listing page.  As a buyer (and I buy alot), I never notice top-rated status to be honest, only neg feedbacks so I can get a feel for the chances of receiving the item I paid for.  I'm not aiming for premium status as I won't ever offer free postage on all listings unless everyone else does.....   As for listings not making the first page in Best Match, well, I can't answer that if it's a problem, but I like to think that buyers don't rely on best match for searches or only look at the first page - I never do and I humbly know that I'm not unique.  I didn't notice any difference in sales once I made Top Rated I have to say, and my other selling account I started recently seems to be doing ok without it.

SO... after losing top rated there's still alot of room for alot of low DSR's before accounts get restricted, which would be something to worry about.  But if I keep up my current standard I'm pretty sure that won't happen.  My aim is to continue to avoid negative feedback and keep selling.  And smiling!