It does it you use the filters well, the more narrow your search terms & filters the more accurate your results will be.
No, it often breaks with narrower filters. The "All amazon sold items sorted by price" preset has been broken for weeks
That is a broad filter, use that preset then open the filters and select a category or use the drop-down menu next to the search bar and select a category then hit go and it will sort much more accurately. To get it even more accurate you can open the filters and select a price-range and it will pull up much better results (the smaller the price-range, the more accurate). I have been using this method for about a month now and it is very reliable.
In the past it was 100% accurate without the need for reducing the price range. It would immediately give the results expected. For example right now it returns random magazines at ~$5-10 which doesn't make sense at all.
That's due to amazon changing things so now the general results are a hot mess. It used to work just fine, then it only worked if you selected a price-range and now it doesn't work at all unless you select a category. They killed off searching for Addon items too unfortunately and that has affected looking for subscribe & save items a bit too. Not much that can be done about it unless someone figures out a way to have it search through each category separately then listing the results but i'd imagine that isn't as simple as it sounds.