Well.... De Neve is a lot nicer. The Halls are more fun...
Halls
Pros: More fun (maybe), more people, doors open directly into the rooms, cheap
Cons: Dirty, old, smelly, far
De Neve:
Pros: Pretty, clear, your own bathroom, more 2nd years, closer to campus proper
Cons: Cost (~1500 more), quite as death, the lay out of the room makes it hard to see inside from the hallway