Hi @fmassa,
Thanks for the great references.
Is there an intent to release any unified pytorch API/project for object detection ?
This is done recently by tensorflow (https://research.googleblog.com/2017/06/supercharge-your-computer-vision-models.html?m=1 250).
This kind of API can help reasearchers to easily :

switch between meta-architectures (SSD/Faster-RCNN) and base architectures (Resnet/Inception/…)
test training tricks such as hard-negatives mining
many other tweaks relevant for object detection