Yeah, not surprised you said that. It's weird. Definitely much slower now - full second delay between mouse input and response. Didn't change any settings whatsoever.
Of course Java is constantly being updated. Wouldn't be surprised if that was the actual cause.
Weird. I just restarted the app after setting the preferences to "Load All Data". The Graph Tab takes a loooong time to load (I've got a lot of data), but once it does, the Graph is still quite zippy. When I had performance problems with the Graph Tab in the past it was due to lots of garbage collections being triggered. I modified the JavaFX code fairly substantially to try to avoid this. It's possible that you're on the edge of available memory in the Java VM and consequently its still doing lots of garbage collection. If you're adventurous you could run the app from the command line and specify a larger heap size:
java -Xmx1500m -jar VisibleTesla.jar
It would be interesting to know if that makes a difference.