1) Compilation speed for a jumbo CNN architecture: Tensorflow took 13+ minutes to start training every time network architecture was modified, while PyTorch started training in just over 1 minute. PyT suits my style of interactive coding far better.
2) Memory footprint: I was able to fit 30% larger batch size for PyTorch over Tensorflow on Titan X cards. Exact same CNN architecture.
Both frameworks had major releases since May, so I am sure these metrics might have changed by now. However I ended up adopting PyT for my project.
Google is actually very scared of PyTorch since nearly all new AI research papers are using PyTorch. This means in 1-2 years or so, most companies will be using PyTorch for training and Caffe for deployment. Tensorflow doesn't even have an implementation of the latest ImageNet winner, DenseNet, but PyTorch does!
I have sources on the Tensorflow team saying they are scrambling to make another higher level wrapper for tensorflow at the level of PyTorch.