The argument for a procure to pay suite is that one system removes the seam between purchasing and payables, where most of the cycle's friction lives. The argument against is that a suite is a larger implementation, and organisations that only have a problem on one side pay for breadth they never configure. Which argument applies to you is answerable from where your exceptions come from.
The case for one system
The order, the receipt and the invoice live in the same place, so matching needs no integration and no reconciliation between systems. Exceptions can be routed back to purchasing without leaving the record. And the open-order report and the accrual come from the same data as the invoice queue. Where the seam genuinely is the problem, this is a real and substantial benefit.
The case against
A suite is configured across two departments with different priorities, which makes implementation slower and politically harder. Modules you do not need still require setup and maintenance. And the payables half of a procurement suite is sometimes weaker than a dedicated payables product, because it was built to complete a set rather than to compete on its own.
How to tell which you are
Look at your exception reasons for a month. If they are dominated by missing orders and missing receipts, your problem is the seam and a suite addresses it. If they are dominated by capture, coding and approval delay, your problem is inside payables and a point solution will get you there faster and cheaper.
Questions people ask about procure to pay suite
Can we integrate point solutions instead?
Yes, and it is a common and reasonable architecture. The cost is an integration to maintain and two vendors to manage; the benefit is choosing the best product for each side.
How long does a suite implementation take?
Longer than a point solution, and the variance is mostly about how clean your supplier and cost centre data is. Cleaning that first shortens everything.
Should payables or purchasing lead the project?
Whichever owns the biggest share of the pain, with the other genuinely represented. Projects led by one side without the other reliably produce a system the other side works around.