If you occasionally (or often) cut hinge mortises for small boxes, clock doors, etc., you might enjoy this tool.
Although not specifically touted for this purpose, I find it perfect for making the final pass over the mortise bottom to ensure that it's flat and square to the case, and the exact depth for the hinge. This is a problem I've always had, would fuss inordinately to get it right...and often mess it up. I've found that a well-cut hinge mortise is never noticed, but an ill-fitting one stands out like a runny nose. Another use is to cock the plane slightly so you're using the point of the blade, run it along and scribe the bottom of the mortise prior to cutting...ie, use it like a marking gauge. 55 bucks may seem like a lot for a tool to get the bottom of a hinge mortise flat, but having used it this way for awhile now with predictable and satisfying results it doesn't seem like much at all. I've tried using my trim router with some success, but it's difficult to keep it square on the edge of a workpiece, it still leaves a fair amount of chisel cleanup...and somehow it just seems like too clumsy a tool for the job. With a couple of chisels to remove most of the waste and the router plane for final cleanup.....pretty quick it's miller time.