Its a heavy framework, but proof to be quite handy.
But running on firefox is quite a problem.
As the longer you are using it, you will realise the memory slowly hike up, and you might be ending up having the entire browser slower and slower.
While in chrome, it works pretty smooth the entire time. So far havent notice any significant memory hiking. And performance changes have never been felt.
And comparing both chrome and firefox performance, chrome works faster in rendering the ui.