Which is more important? Features or functionality?
Example. Until recently I was following my tweets with Tweetdeck, which allows you to remove read tweets, sort people you follow into groups, it even hooks up to Facebook. There was just one problem.
It doesn't work.
It never remembers what you've removed, and recently it's been asking me to download an update, but whenever I try, I get an error that the computer doesn't recognize a file it's trying to open.
So I gave up and switched over to Tweetie, the Mac version of the iPhone application. No groups, no removal of read tweets. It's not nearly as customizable. But it works, and it does what it claims to do. Clean interface, good symbols, and functions at a reasonable level.
Life is about the niche. Do what you do, and do it better than anyone else, even if it only is the one thing.