Filtering by rarity is worthless, they're already color coded. Let me filter by stat or flag items for a build and filter by those.
Real question, is the stash even big enough to need search options?
its like 5 pages each 50 so 250(IIRC)? and yea the search is good, if you just throw random legendaries in there to extract later (like me), and you then needed a specific one to imprint.. have fun hovering your mouse over every item, finding all your 15 differnt "spell X deals Y% when whatever happens", lookin for the highest % one now should be much faster!