Let's look at your source of points:

AA - can be used for travel on any OneWorld partner. CX is wonderful in F. flies between the US and HKG, then to many onward destinations. You can get oneway awards with AA miles. You cannot get any stopovers. I believe that an award in F is roughly 140K roundtrip.

AMEX Membership Rewards - my personal choice is to move points to ANA, but others prefer Air Canada or Continental. Any of them part of the Star alliance. ANA has varying award levels depending on the season. Their awards are mileage based, and allow stopovers. I just redeemed 90K points for a middle tier season for business class to Singapore with a stopover in Japan on the return. Be aware there is a significant fee to get an award using an international carrier. I think mine was about $400.

Here is an excellent analysis of good and bad uses of Membership Rewards:

http://boardingarea.com/blogs/onemil...ewards-points/

Personally, I find Star awards more flexible for Europe than awards with AA miles. There are more partners that allow a lot of destinations in Europe. With AA miles, you cannot redeem on BA from the USA-UK.

Starwood AMEX - I'm a great fan of free hotel nights. A nice night can be very expensive, and add significantly to trip cost. However, if you only have 100K AA miles and really want to fly CX F RT, you can move Starwood points in blocks of 20K and get a 5K bonus for each to many airlines.

As for C vs F, you really need to do an analysis of how many points the awards take and how many you expect to have. F can often be a delight to fly, but C can be a solid product, particularly if you are used to flying Y.