IIRC they are all just front ends for Expedia(AMEX/CITI), AMEX's might have a touch better customer support but its still just a front end. I personally would only ever book Hotels through travel portals. Like if its an independent hotel or in a brand I dont have loyalty with, then I would be fine booking through a travel portal. Everything else gets booked directly. At this point, at least the 3 main US carriers. everyone is on a race to 1cpp with delta being there already. I am using a "Travel Points" ecosystem but in reality its just cash back(BoA Premium Rewards.). So IMO just do cash back unless you are tied to a specific brand.

As for Chase, at this point, the best value for points is to transfer them to Hyatt and hope they have a property near where you are going.