There have been some performance issues that were helped by the installation on PageBlaster Free but then this led to some caching issues which haven't had too big of an impact. Basically, content doesn't always appear updated when updated. You can clear your local cache and see the new content. Once I cleared the cache and reloaded the page while pressing the Ctrl key. Page Blaster reports that this will also clear the server cache. But the page loaded old content shortly thereafter.
So there are issues like these. But overall, there are some great new features and DNN provides for additional features to be added on a regular basis, which we are very excited about.