What's wrong with it? Just curious, I use Outlook for work and my main pet peeve is that i) local search isn't great and ii) in general, the application UI is

What's wrong with it? Just curious, I use Outlook for work and my main pet peeve is that i) local search isn't great and ii) in general, the application UI is very 'delicate' -- e.g., I have mail rules that move mailing lists to a folder. I browse through them from time to time but housekeeping those is a nightmare-- Outlook consistently freezes while deleting larger numbers of email.