Cardiff is LOVELY!
Moved here 2 1/2 years ago when pg with DD, and we love it.
Wherever you lived in Cardiff, you would be under 30 mins from Llanishen.
Nice area on that side of the city are Roath/Penylan/Cyncoed. All near Roath Park, which is fab, with big boating lake, playground, playing fields etc.
Other area that are nice for family life are Whitchurch/Llandaff/Radyr/Pontcanna.
Avoid: Splott, Grangetown, Llanederyn, Ely, Rumney, Llanrumney
Is you wnat some advice on estate agents to look at, let me know as am property junkie and spend hours looking online at houses I will never buy.
I'm not really clued up on schools, as our local one is dire and we have got DD down for private. There are lots of nurseries around though-I've been to see dozens, so if you get to that stage, let me know and I'll tell you my thoughts.
Fab thing about living here is that you are 30 mins drive from proper countryside, and 40 mins from lovely beaches, but only 2 hrs by train from London, and straight onto motorway to get anywhere.
The airport here is good too, only 30mins from centre and flights to most places.
AND there is a MASSIVE Morrisons in LLanishen!