I've owned both since the mid-1980's, and still use both for occasional projects. Both accessories are easy to learn, but
practice is a must! Just use up some of those plywood scraps.
The Rout-a-Signer is designed for engraving lettering or other designs, using templates (non-freehand). The router uses a bearing-bit or router template guide to trace around the inside of the template. The lettering/designs sizes are limited to the size of each template. Great for carving all types/sizes of wooden signs. IMO, the purchase of additional size lettering templates AND a router template guide kit is a big plus for its usage.
I've included an Amazon link so you will be able to search for the many available templates and template bushing guides. Rockler and other vendors have similar items, but at higher a pricing.
https://www.amazon.com/s?k=router+template+inserts&ref=nav_bb_sb
Sample kit:
* If ordering a bushing guide kit, make sure to note which brand router(s) are compatible. All router sub-bases are different. Also, I would suggest a metal guide kit for longer wear, as opposed to a plastic material.
The Router Pantograph is designed to enlarge or reduce a drawing/design. The print is then transferred to the wood, with use of the router. Transfer is
freehand, instead of having to use a template. The nice feature is that any straight, cove or vee-bit can be used for the process.
Any wood can be used with either accessory. However, some hardwoods may tend to show burn marks from the router bit, depending on the router RPM. To compensate, I invested in a portable router speed control from Rockler -- only because the
lighter-weight router that I
dedicate for use with both accessories, isn't variable speed.
In closing, make sure your workpiece is secure when using either accessory. You can use clamps, but may have to move them around when routing. To make securing easier (in most cases, no clamps), I use a bed of woven shelf liner underneath the workpiece. The liner is the same material used in making the marketed router pads.
Here's what I use: