I've been running it for a few days now. I had a strange problem whereby if you clicked on any of the links in the toolbar it would visit that page, but hide all the menus & toolbars! The only way back was to close the browser and re-open it.
I spent some time removing the extensions I had installed and the problem cleared after I removed FeedView. I then reinstalled all the extensions I removed (including FeedView) and the problem has stayed away. Very odd.
Just something for others to bear in mind if they run into the same problem
Ben