As in the title really - what plastic shuttlecocks best mimic the behaviour of feather shuttlecocks?
According to this badminton site:
Note that while all feather shuttles have actual cork for the “cork” portion of the shuttle, some plastic shuttles use a firm foam “cork” as the part of the shuttle that you actually hit. Know that these materials have a great impact on how the shuttle plays and, if possible, I would recommend that you stick with shuttles with actual cork for the head. There are a number of plastic shuttle manufacturers but the Yonex Mavis line seems to be the most popular (though others from Carlton, Head, and Black Knight are popular as well).
From Yonex USA site, the flight pattern of the Yonex Mavis 370 comes close to that of an actual feather shuttlecock:
From one Amazon review for the Yonex Mavis 2000:
This is a very good shuttle if you are looking for durability. The flight is very near to a feather shuttle, but it falls just a bit short because there is nothing like the weight distribution of a feather shuttle from which you get better control and feel.
These links are all subjective, but all seem to indicate that nothing really matches the performance of an actual feather shuttlecock. Durability seems to be the largest advantage of the plastic versions. I hope this info will point you in the right direction for your search - please let us know which brand/model you decide on.
I know this post is a couple of years old but a British company has just started making these bird2 shuttlecocks.
Played with them for the 1st time today and my initial reaction is that they seem very good.
I'll update this answer if they prove to not be very durable.
N.B. I am in not affiliated with Bird2 in any manner.
Having now used this a fair bit they are really nice to play with and a lot more durable than feathers. However we managed to destroy 3 of them in a single session recently so they are definitely not as durable as standard plastic shuttlecocks.