Whether it's easy to book on the Chase portal would not be the issue for me. The issues arise when you need to make a change or get a refund. I've had absolute nightmares making changes / getting refunds with Amex Travel which is outsourced to Expedia such that I generally won't book through them anymore. I'll book through C1 just to use up my $300 travel credit. Otherwise, I book directly with the airline using my Amex Plat for 5x MR.