Caseware's Working Papers is more flexible than Engagement CS. For example, Engagement CS doesn't work well with paperless payroll engagements because the engagement date pulls from the G/L module. Therefore, if it is January and you need to do January payroll and last year's W-2s and accounting, you are out of luck. Also, Working Papers works better for consolidations. I haven't used the CCH product or the Accountant's World product.