Our company changed phone systems in our call center two years ago, and with that change, the WFM and QM software were changed. We went with Calabrio based on the recommendation of our vendor.
Dec 2018: We have upgraded to Calabrio v.10 just this weekend. I will be reviewing version 10 after I've had a little bit of time to use it.
I cannot speak about the difference for the QM software.
My main use is of the WFM software. A few of the features were "nice to have" features, but version 9.3 had some "deficiencies". The main problem was not being able to run scenarios in a pseudo scheduling area, so the way Calabrio is now, agents can possibly see test scenarios.
Another problem is the Time Off Request area. Agents are not able to cancel an approved request through this area. The sorting/filtering could be improved upon greatly. We are scheduled to upgrade to version 10.0, which will resolve many of the issues we do not like about the current version that we are using.
Update: We are still on version 9.3 and looking forward to upgrading.