For me, the most important part of flying INTL up front is being able to sleep. In my experience, although the AC seat is good, the Polaris seat is better. To my aching back, the fully reclined AC seat feels like a seat that's been reclined, not unlike a fold-out couch. The Polaris seat when fully reclined feels more like a bed. And again, this opinion is distinctly subjective.

The price differential quoted by the OP might be enough for me to consider flying AC, though.