Both villages are fairly close to me - what make you select those particular two as they're quite different?
Middleton is close to the A47 - it actually cuts the village in half - which makes it quick to get to Kings Lynn and relatively convenient for Norwich. The village has a pub with good food and a primary school, although that has had issues recently. I don't know the village well enough to comment regarding community feel.
Runcton Holme is more isolated but has a great children's park, social centre and Brownies/Cubs, etc. It has a primary school but I don't know much about it; it has Downham Market Academy as its catchment high school, which has problems at the moment. Downham Market is closer than Kings Lynn and I would say is where most people shop, although the shops there are fairly limited.
Many schools in the area haven't done well in recent years, in terms of Ofsted reports, but the primary schools generally seem to be improving lately. High Schools are a mixed bag.
In between Middleton and Runcton Holme, Shouldham and Wimbotsham are particularly popular villages; the property prices are slightly more expensive for the area, although still cheap compared to Brighton. Both have good primary schools, children's play areas, a pub and a community feel.
We really like living in this area, it's a good place to bring up children and we don't regret moving here but it is very different to Brighton (I used to live there), so may be a bit of a culture shock at first - particularly if you have a teenager. As a previous poster has said, Norwich is probably closer to Brighton in feel and has more going on but with a slower pace of life.