As per http://javafx-jira.kenai.com/browse/RT-11253?focusedCommentId=85027&page=com.atlassian.jira.plugin.system.issuetabpanels:comment-tabpanel#comment-85027
When content inside a ScrollPane is transformed it must be wrapped in a Group so the bounds are calculated properly.
In my application I have found that when I scale the content that is wrapped there is a massive drop in performance. When the scale on the wrapped content is 1.0 performance is reasonable.

Run the attached test case and look at the times printed to the console as you drag nodes in the scene. Hit the one of the scale buttons and drag again. Times printed are approx 100x greater.