Wine Bottle Stoppers

I took a class on making wine bottle stoppers this last fall at the Cleveland Woodcraft store. Of course, Woodcraft sells the kits to make the stoppers.
The kits include the mandrel to hold the wood for turning, a drill bit to create the hole to attach the wood to the bottom, and four of the metal lower sections, and the plastic washers to seal the bottle. The metal stoppers offer the advantage that they will not pick up the taste or odor from other wines. You furnish the wood and turn it to whatever shape to become the top, decorative part of the stopper.
The class was helpful with several hints to improve the chances of successfully turning the decorative wood top. The kit is set up for you to drill a hole in the wood, thread the wood onto the mandrel and then turn the wood. Once done, unscrew the turned top from the mandrel and thread onto the metal post of the stopper bottom.
The class suggested drilling the wood blank to accept a 1/4"x20 threaded, brass insert and using CA glue to assure the bond between the insert and wood. This eliminates the chance that a "catch" while turning would strip the threads in the wood and make it difficult to finish turning or to attach the top to the threaded lower section. That suggestion alone was worth the trip to Cleveland and the cost of the class.
I was disappointed, however, when I left the class to buy the kit. They were out of the kits. I actually ended up buying the kit in Columbus when I was visiting there a week or so later.
I have had mixed outcomes mostly because I used some push-in brass inserts instead of the threaded inserts. The deal I got on the push-ins was totally wiped out by the wasted wood when the inserts broke loose and spun in the wood (but refused to dislodge completed!). The stopper on the left is cherry while the one on the left is bubinga. This is one of my 2007 "Unfinished Projects." One down, a lengthy list to go.
Our only problem with the wine bottle stoppers is that we almost always finish a bottle once it is opened - so why do we need one of these stoppers?