I've designed such a system a couple of years ago, too. When users complain about Excel, now that sounds to me: They're really saying, "I love Excel". Don't

I've designed such a system a couple of years ago, too. When users complain about Excel, now that sounds to me: They're really saying, "I love Excel". Don't forget it's only a tip of iceberg. Users will complain more about missing features after you built something users have cared about.