Marketo has been fairly slow for us for several months now. I'm kind of curious if it has anything to do with the number of approved assets that we have (we leave them approved so they still show up in the analytics reports).
Our instance is constantly slow. Reports take a very long time to load and exporting lists take even longer. We have been experiencing this since the interface change (not sure if that has anything to do with it). We are constantly opening tickets. Hope it turns around soon.