I would tend to agree with some of the comments made by WHBM, however times have changed and since devolution and the establishment of a Welsh assembly (which I think is a complete waste of public funds) a greater demand has been created for links between Cardiff and the Welsh regions.
Due to the topography of the Principality surface transport links are poor, which makes air transport an attractive proposition.
Whilst RAF Valley has first class facilities, such as radar, ILS, fire cover etc.....it is situated on the far North West corner of Anglesey which is very sparsely populated.
If a North - South link were to work then I think Hawarden on the Cheshire border would be the obvious choice as North East Wales is the most populous region of Wales after the South East. Hawarden too has first class facilities and has excellent road links to the rest of North Wales and the North West of England.
Rabbs