Peter I normally just use a square block of some appropriately sized panel board as a pusher block and hold my workpiece to the pusher block against my fence. so do a few other members. I'm not saying that that sled wouldn't be a nice tool to have but it looks pricey and it is certainly something you could work around.
For one router table I have I made a simple coping sled that was guided by a strip of wood that followed the front lip of the table. I made it out of scrap and it cost nothing. Then if you set the fence to right depth of cut you want you just register the end of the rail against the fence and then route it. In neither case of the ones I use does the work sit on the jig. With some routers and some bits the loss of depth from the thickness of the sled could be an issue.
Someone I consider a master woodworker once told me that a master woodworker is not someone who never makes mistakes. He is someone who is able to cover them up so that no one can tell.