I found this interesting looking 3D-printed horn mouthpiece on Shapeways: http://www.shapeways.com/model/790451/fluted-french-horn-mouthpiece.html?modelId=790451&materialId=39

The designer claims that "you can better achieve that buttery smooth sound that you've always wanted" due to it's "strategically placed vibration-dampening fluting", whatever that's supposed to mean.

I'm trying to decide whether paying the $53 will be worth it. I'm surely not going to replace it with my current mouthpiece unless I fall in love with it, but it may come in handy for specific pieces if it does what he claims.

Any thoughts on this? Is it worth the try?

I find mouthpieces very specific to the horn they are played with. Each of my mouthpieces are designed for the specific horn I am playing. The advertisement you link to has no specifics for dimensions, cup depth, shank length, bore, throat, or backbore. Nor does it specify the type of rim you are putting against your lips.

Who knows what the venturi is going to be when the air exits the shank into the leadpipe of your instrument. A good player can get that buttery sound from pretty much anything.I suggest your stick with a known mouthpiece until your skills are at a consistent level that you can tell what an equipment change does to your playing.Then if you have extra cash you want to throw away and don't want to give i to a charity, then you can spend it on a toy like this.

Yeah, I'm not going to buy this. I messaged the designer of the mouthpiece and he admitted that he knew nothing about music and was just paraphrasing what other horn players had said about the mouthpiece.

I came across this as well, and put it to a physicist friend. His response was that unless something is done with the rest of the horn, any effect it may have will die quickly once entering the straight section of the tubing. Although I should have a mouthpiece for each horn, at this point in time I do not. But I'm loving my Houser San Francisco model. I had a special rim cut from his long sheet of historic models. It is a mid-60's Chambers which is what I'd been playing on. Just great, and works pretty well on my Holton 181 and Paxman 25a, but not so well on the Geyer F single.