It's easy enough that even my non techy friends can use it! The interface is intuitive so I don't have too many complaints about how its designed or implemented in general (although there are some minor things like adding more fields but they're not deal breakers).
We've been using ProCru since we started our business almost two years ago now with no problems at all - everyone loves being able to see everything from one place without having multiple spreadsheets open across different devices/computers etc which was always an issue before this system came along!