In reply to jussy:
I've lived in South Wales for a while now and climbed all over Pembroke, the Gower and the mank that is the Valleys. I can't comment on Devon, never lived there. To answer the question 'is there much to do for kids' ala Dublin, then bearing in mind Swansea is a lot smaller, no, not as much. Dublin is a capital city of 500k and Swansea is on the edge of a rural community and has a population of around 200k. However the Gower is lovely, Swansea bay is great. There's LC2, which is a large water park pool thing. There are plenty of museums, but nothing amazing. There's also lots of castles. There are more NT properties now than were a few years ago. Lots of great walking, biking, climbing etc. The Brecon Beacons are around an hour from Carmarthen, with the west side of the range even nearer. Cardiff is about an hour or so from Carmarthen and there's definitely more to do, Cardiff Castle, Castel Coch, St Fagans, the Bay, Cardiff Museum/Art Gallery. Just to name a few.
Less sure about the schools. Also generally, there's not masses of jobs around South Wales. It's still got some areas which are fairly 'deprived' in an economic sense. Depending a bit as to what you do, if you don't like the job/want to progress is can be hard. Depends a lot on your career. A lot of folk do still leave for London.
John - To answer your question about integrating into a Welsh community, it's not a problem. Pembroke especially (as others have mentioned) isn't really very 'Welsh', if anything it's the other way. Carmarthen is more 'Welsh' but again it's a lovely friendly town. I've lived in Wales for over 15 years, 5 of it in the mid/west Wales area (Lampeter and Aberystwth), everyone is lovely. Small friendly communities and lovely countryside. The only time you ever get a bit of vague banter is when the rugby is on. If you go in the pub in an England shirt when a match is on, you'll get the piss taken. But it's all good natured and I've never had a problem personally. Hence the dislike.
Also, Jussy, if you're Irish, then you'll get a free pass. No worries there. But people are just nice around here. As you can probably tell I love it here.
Post edited at 18:42