Hi boyo,
I did my PPL split between Cardiff and Pembrey. It's true about Cardiff being an excellent place to fly, the only draw back I found was the fact that you could be kept waiting in the circuit/on the ground for commercial a/c to land/take off.
On some occassions this took anywhere between 5 - 15 mins depending how busy it was. This is then 5 - 15 mins your paying for when your just twiddlings your fingers.
On the other hand, smaller airports like pembrey have little or no traffic. Not sure how close this is for you, but I can recommend the club there for quality training at reasonable cost. Mail me if you want any more info / insight into either clubs.
G - HIGH