Evaluation code against MS COCO is included in the repository, both for bounding boxes and segmentation masks so it should be easy to run (but takes a long time).

We should publish more details, though. Thanks for bringing it up. Our implementation deviates a bit from the paper (as mentioned in the documentation), and optimizing for COCO was a 'nice to have' rather than being the main objective. We got pretty close to the reported numbers (within 3 to 4 percentage points) but that was with half the training steps compared to the paper. We'll try to add more details over the next few days.

Did you create an account just to criticize the original posters work?