Aside from their looks, they are excellent pipes. I was actually quite surprised at how well they smoked, figuring they were some sort of a gimmick pipe. The ring type filter is not required and you can also use a small piece of pipe cleaner for the same purpose. It the tobacco is moist I would recommend using the filter to absorb the moisture, that is all they are really for anyway.
The current bowls tend to have a number of fills so I go for the rusticated ones. You can always check before hand. They are sturdy as all get out. If you have the chance, go for the Hunter series stem, they are all black. Not sure which stores sell the black ones but I think 4Noggins can get them via special order. There is also a chap who sells them on eBay.
The regular bowls are good for a 30 minute smoke. The Classic bowls are larger and good for an hour or so. The Hunter bowls are small, good for a 15-20 minute smoke or a strong tobacco. One stem and a couple bowls sets you up nicely.
The International series are more like regular pipes in appearance and I believe you can remove the stem on those. The regular line you cannot remove the stem, it is crimped into place. A regular BJ Long pipe cleaner works, you do not need the extra thin ones made for Falcon.
All that said, if you get past the looks, they are an excellent pipe for the money.