performance millions of records

what has been your experience with the product performance once the pod has over 1 million records?  We are currenty on a shared pod, and particularly when our webservice integrations are running the performance is poor.  Reporting is also performing slowly.  I'm wondering what other's experience have been, performance wise on a shared pod.  With that size are you typically using on-premise, single pod, or even downloading your records to other internal reporting servers?