Today I rolled the dice. Bid on an old Cona tabletop on Ebay, a post-war model, that doesn't have a filter or burner. But, for less than the price a new Yama, I thought it was worth a shot just based on the charm factor. It's got that grimey, vintage charm that people of my generation tend to like:
http://www.flickr.com/photos/hvbean/5426852918/sizes/m/in/photostream/ (It looks like the one of the left.)
Some risks here. I imagine there are small dings on the lower globe, which doesn't bother me much, but if there are any hairline fractures then this unit would be strictly for display. Fire + vulnerable glass and you're asking for it.
One of the cooler things about vacuum pots is their versatility. They can take a variety of filter media. These conas are designed for glass rods, which have this bumpy surface that blocks most coffee. The coffee then filters itself, in theory. The problem with glass rods is, they make it difficult to stir--if you dislodge the rod, then the grounds will just fall into the bottom bowl. On the plus side, the unit becomes pretty easy to clean.
My favored approach is to use a two-part filter mechanism. That lets you choose between metal, paper, or cloth filtration. I'm partial to cloth, which is usually difficult to clean. The standard Yamas come with a cloth tied around the filter holder, and sometimes coffee grounds will pass through the filter...without you knowing about it. Also, if you're using some sort of detergent, the granules are more likely to get stuck, which is kind of gross. With the two-part filter, however, you can *completely* remove the filter, making it easy to clean both sides. ROASTe used to sell this apparatus, but I'm not sure if they stock it still.
Worst case scenario, the Cona is a dud and I'm just left with a nice-looking stand. Fortunately, the TCA models by Yama/Hario are modeled after these old Conas, so I can just swap in new glass for the old. It'll be a while before I get to use this thing, but it should be fun, so long as chards aren't involved.