Keep hold of the return ticket, give it a fortnight and you'll be back to Rockies before you know it. UK is now a melting pot of chavs, East European criminals, bent politcians and $hit weather; and thats the good parts!
The one institution that will not get hammered is the clinical side of the NHS. If the NHS gets touched at all (doubtful) it will be to deconstruct the stupid layers of management and the QANGOs and free up clinicians to do what they do best. Triage-lead priorities are far better than target-lead.
In terms of professional experience you cannot do better than the overcrowded, understaffed British hospitals, in terms of a frustrationless work environment you may be better staying where you are.