Personally the AH has been my favorite part of the whole game.
Meh, atm the AH is to cumbersome for my taste.
You can't sort by time left. Would have been fun trying to get items for cheap just as their about to run out.
You can't search for set items only. For some reason they are part of the legendary items.
You can only search based on 3 affixes, why limit it at 3 affixes? Makes no sense whatsoever.
No way to just search for all weapon types at once, only those that the class you've currently selected can use.
Searching for Blacksmithing plans, you can't actually see what kind of item the plan is for. You'd have to go and use the diablo 3 database or something to find that out.
If I want a helmet with all resistance, why can't I sort through the helmets so I get the helmets with most all resistance at the top of the list, and the ones with least all resistance at the bottom? It's such a fucking chore having to manually check each and every helmet even after I set a minimum value for a certain stat.
etc etc.
they need to revamp the AH tbh, it's badly designed atm, which makes it annoying to use imo.