Product review (5 stars): Works fine.
After a month with the new extension drain installed, there are still no water on the floor.  Apparently, it works.
I rated this a 5 as its doing the job and wasn't particularly difficult to install.  The top cup part needed more pressure to put on than I was expecting but at the same time its firmly installed and not likely to fall off.

Looking at the design of the original "duck bill" valve, its easy to see why it failed.  Evidently, there is enough particulates in the moist air and discharge that it eventually clogs up the "duck bill" type of valve.  Chances are that this new design will eventually clog up too but it may be so long that the refrigerator has reached its end of life anyway.  The design of the new drain is such that particulates should collect at the bottom of the elbow but with a large diameter it'll be a while before it clogs up.  Even then, provided your refrigerator is still running, its easy and cheap enough to replace than to clean.