OK experts, we are looking at SFO-SIN business class award booking using either KrisFlyer or Aeroplan award points transferred from Chase Ultimate Rewards. Award points required seems to be less on Aeroplan than on Krisflyer. Also, Aeroplan points transfer almost instantly from Chase whereas KrisFlyer points can take up to 48 hrs. Are there any negatives to using Aeroplan vs Krisflyer?

On a separate issues, has anyone had issues with seeing award availability on Krisflyer, then waiting the 48 hrs for the points to transfer, and then not seeing the award there anymore (realize this is always a possibility)? Is it possible to get Singapore Airlines to hold the reservation while the points transfer?