DPS calculator

Does anyone know a proper (accurate/automated) DPS calculator to pre-plan a build?

1. POE skill tree: https://github.com/EmmittJ/PoESkillTree
This tool doesn't seem to allow you to swap gems. Furthermore, it's DPS calculation deviates significantly from the in game tool tip DPS so its accuracy is questionable. The tool does however allow you to load your skill tree/items automatically.

2. SpellDPS: http://www.poesp.com/tools/spelldps/
The latest posts I could find mentioning this tool date back to 2014. Not sure whether the tool is still up-to-date with today's game mechanics. Furthermore, entering all this information manually is a pain.

A DPS calculator would be great to answer certain questions like: as an endgame witch, should you go for the extra cast speed, or extra spell damage. There are many more trade-offs you would like to simulate to see the effect.

Maybe this might help: http://www.pathofexileitems.us/pathofexile-weapon-dps-calculator