I would agree that everyone should experience smoking a Calabash. I have a Pioneer that was crafted most likely during the 70's. They are ideal for taming very strong blends, such as brown ropes, or Latakia heavy blends. They are also great for smoking Virginia flakes, as Virginia's tend to create a little more moisture in the smoke stream.
What makes the Calabash work so well, is that it has a second chamber that is large enough to not only collect moisture from the smoke stream, but it will also cool the smoke. This is where most of the newer Reverse Calabash pipes are deficient. Their smaller second chamber collects moisture, but usually isn't large enough to cool the smoke the way a traditional gourd Calabash can. Some folks shy away from a gourd Calabash because of the size, but the size of the gourd is what makes the pipe perform so well.
When looking for an estate Calabash, try to find one with a meerschaum bowl. Some models were crafted with porcelain bowls, which will appear somewhat thinner vertically than the typical meerschaum. The meerschaum bowl will perform better, be cooler to the touch, and have better longevity than a porcelain model.
There is a guy named Anthony Harris out in Kansas City who makes some very effective double chamber pipes from briar, but the chambers that are most effective tend to be rather large. If you are form follows function minded, you might be interested in one of his offerings. Here is a link to his site for anyone who is interested. http://acmepipes.com/Home.php
BriarWorks out of Nashville, TN makes some really nice Calabash pipes from briar, with magnetically attached briar bowls, but they are pricey.
Here is a pic of my Pioneer Calabash I picked up around 10 years ago. If I remember correctly, I paid around $75-$100.