What are the differences between the older row_number() and the newer OFFSET + FETCH based pagination in SQL Server?

Using ROW_NUMBER() works fine - it's just more work than necessary; you need to write a "skeleton" CTE around your actual query, add the ROW_NUMBER() column to your output set, and then filter on that.

Using the new OFFSET / FETCH is simpler - and yes, it's also better for performance, as these two links can show you:

• New T-SQL features in SQL Server 2012
• Comparing performance for different SQL Server paging

So overall: if you're using SQL Server 2012 - then you should definitely use OFFSET/FETCH rather than ROW_NUMBER() for paging