Each country has its own benefits.

I, personally prefer the UK Centurion, for the following reasons:

1. It is cheaper (£650 per year instead of $2500)
2. You can have multiple supplementary cards for free.
3. You get two priority passes - which give you access to an airline lounge just about anywhere in the world.
4. VS Lounge access.

The airline elite memberships don't really mean much to me - I have elite status on all the airlines I fly regularly anyway. The only thing I would like from the US program is the Hyatt Diamond status - which I may use once or twice a year.

You can send you MR points to any airline you like by first converting them to Starwood points, though this results in a devaluation.