Reply by teejk

either one is essentially the same tool…high speed motor with a blade/fence…given that the PC557 is a dedicated machine and the fence/alignment marks are machined for a single purpose, most likely more accurate than a router “add-on”.

but now into “real-world”, if this is a single use project, then if the router attachment is significantly cheaper and you have some scraps to play with before you wreck your project, then go for the cheap one (as long as you don’t need to use the router in the mean-time). “add-ons” (e.g. a drill press mortiser) take the primary tool out of service and take time to assemble/remove/re-assemble.

the 557 was popular for a few years (thanks to Norm who got it for free)...although I’ll keep mine, it might be one of those dust collectors for a lot of people and a used one might be found for a few $$$ (just DON’T drop it!!!...it seems to be like buttered toast and will always hit the floor on its weakest point).