Obviously there's story implications, but the only thing I've noticed reward wise was the Hylea food. Do any stat bonuses come over for pool sacrifices or absorbing souls from the machine etc?

Got Hylea food without importing. If you did nasty things for stats in PoE1 you will get them eventually (not upon game start), but you can specify you did that in the history creator anyway. Josh said minor reactivity for importing saves instead of generating a history. So far there are bugs with both (maybe not after the recent patch), but I expect when all is sorted there'll definitely be no material or content gain from using one over the other.

There was a bug that if you don't use an imported save you wont have the fragments of endless paths on your ship when you start. I confirmed this and it only appears on my imported saves =(.