For a basic ERP (DB with around 150 tables, WinForm app) which would run on a classic LAN network (1 server and up to 25 clients) would you recomend EF4 or DataSet ?
LINQ2SQL is NOT an option !
EF4. DataSet is an old technology, EF is in many ways a reaction to the problems with datasets.
We recently built an app, where part of it was CRUD operations on 80 Tables. Before EF we would have used Enterprise Library and DataSets. We would have estimated 1 hour per table for writing the CRUD operation and the unit test. With EF this was replaced mostly with autogenerated code.