During my developement process I have itemizing those weaknesses and issues which were unexpected or disappointing.
Mac 'finder' is probably the weakest point using a Mac (OSX). The interface lacks a command bar for easy cut and pasting of paths when you need to navigate between file exploring and another program.
Another alternative is Commander One
Easy Find - location files quickly, both filename and file text search.
CCleaner - remove junk from your Mac.