Turnaround time for legislation will vary depending on the size and complexity of individual Acts. Some Acts are very short and simple, such as the Anti-Slavery Day Act 2010. Others are very long and complex with many amendments to previous provisions which must be added to the database, such as the Equality Act 2010.
Acts generally take longer to do than SIs because we add rather more information into the database for an Act than for an SI. Also, there is generally a glut of legislation before Parliaments rise for summer recess, so the markup process will take longer than usual around then.