Better yet: Stick with Mongo, create regression tests, switch out or simplify the framework and add integration testing. It is often viable to take the meat of

Better yet: Stick with Mongo, create regression tests, switch out or simplify the framework and add integration testing. It is often viable to take the meat of a system and place it in a new framework with some alterations. And for the performance issue, just identify what causes it by timing parts of your code. I'm guessing home grown database wrapper.