I feel that given common repetitive tasks, it's better to implement keyboard shortcuts to allow the power users to gain efficiency.
Honestly, you might've just answered your own question.
Some people use exclusively the keyboard, some people use it a lot, some people don't use it at all.
Take into account the following
- Notify the user of availability of said key-binds
- Use common key-bind patterns (don't use ctrl+c to create a new item,
etc)
- Try to make everything that has a shortcut also accessible
through other means (so that there's as little "keyboard-only"
functionality as possible)
Additionally
- Try to take into account a lot of power users use a combination of mouse and keyboard so you'd want everything easily accessible under that one hand
- where possible, consider left and right-handed shortcuts, or a switch between them