another issue I encountered last night was that when switching screens using the device icons at the top of the screens some of the device dialogs would not render completely, in particular the "wifi" dialog was empty.
To me, that's indicative of a busy cpu, or some device not responding, and the 1/10th transfer speeds over wifi
would also be indicative of that also...
anyway reverted back to 2.5.2 and was able to get some useful imaging done, not sure when I will attempt to use
3.0 Beta again at this point, as there are no features that would make it worthwhile to risk the upgrade again for now.