I've used serpbook, serpfox, intelliserp, micrositemasters, and thought of serpbuddy. Honestly, not impressed with them. They all either show inaccurate rankings or update once a day (again with inaccurate rankings). I didn't like the support of one of them either, so I didn't go with them. I need a keyword tracker that shows accurate rankings, updates multiple times a day, and also has an on-demand update feature. Anyone know of any?