All make very valid points with regard to competition between TCX and other carriers flying from MAN to US destinations; whether it's a 'Low Cost' carrier offering first class, wide-bodied vs Narrow etc.
However
One other factor which has yet to be raised: A non-legacy US carrier offering low cost Trans-Atlantic flights on narrow bodied aircraft between MAN and major US destination(s).
With the advent of the A321neo, this is a distinct possibility. This may not have a direct impact on TCX as they are already involved in agreements with at least 1 such US carrier.
Exciting stuff!