To me, car points are worthless so always get the airline transfer. But, hotel points? Specifically, SPG points? Good as gold.

As an aside, I used to do the auto SPG transfer to Aeroplan when I first started staying at SPG props as AP had an auto minimum 1K AP points for every transfer, 1.5K for Luxury Collection (at the time). With my math and doing 1 night stays, it was a better "deal" to transfer to AP than to keep SPG points. That is, until I started accumulating bucketfuls of AP miles and had no SPG points.