For those that say that the meerschaum pipes with the screw in tenon, and/or the plastic mortise/tenon; are poor smokers and not worth owning need to keep in mind that everyone is different and has different preferences.
I have a couple meerschaum pipes with screw in tenon's and they smoke absolutely fine, and one of them is one of my best meerschaum pipes. I have a couple with the plastic mortise/tenon and I have absolutely no problem with the draw. I have some really nice and really expensive meerschaum pipes made by some master carvers, and some by some unknown carvers that are lesser quality, and I don't have issues with any of my meerschaum pipes. It all comes down to preference of the individual.