Personally, I prefer Cathay Pacific as an airline in premium cabins as I find their service to be more genuine than Singapore Airlines.

As for the seats, both CX and SQ offer top quality sleeper seats in First and Business Class cabins.

Since you will be travelling via Hong Kong, you will get to experience CX's The Wing or The Pier lounges which are considered the World's Best and I am sure you will enjoy your experience at this fantastic lounge facility.

On the other hand, SQ's lounge at Changi Airport is of sub-standard quality when compared to CX's lounge facilities in HKG.

After all, the choice is yours but I believe you will enjoy the services and facilities of Cathay Pacific more. I fly on both of these airlines and as a tough critic of the airline services, both these airlines of top quality.