The major difference, as I see it, is a tool like the CPS can save you a lot of time when doing large quantities, which would make it worth it. Other than speed for getting the priming done, most hand tools can be hard on old hands and can be quite inconsistent with seating depths. The best hand primer seater I've come to use most is my 21st Century priming tool, which is not only seats my primer's with consistency, but also has good leverage and is very easy on my old, somewhat arthritic, hands. There may not be much, if any, difference on targets, but there are other issue at play when trying to decide which is the better choice.