I would find it very useful to have small changes implemented in Contacts > Reports.
First ... The reports show the total number of contacts over the life of an account. Could it also show the number of active contacts side-by-side. (You can find this information under Contacts > Contacts but a side-by-side presentation of the data would make things easier and clearer.)
Second ... Below that, you can get a number of contacts that unsubscribed during a period of time. It would be very useful to see and compare the number of contacts who subscribed at the same time.
Third ... last ... and least ... It would be useful to specify time periods longer than 1 year for reports.
These small changes could help make a great product even better.