Hi, Jules! Welcome to the boards! Below is a link to an old thread that has several comparison photos between Wink CZ and Asha:
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I've personally owned both, and both are extremely diamond-like and quite stunning in real life. No one ever suspected they were not real diamonds. The main differences are that the Asha has the amorphous diamond coating and is cut to hearts and arrows standard where as the Wink CZ are not, hence the price difference between the two.
The Asha can also be classified as a VS clarity which may make it feel more diamond like knowing it has flaws like natural diamonds.
Wink CZ, like most CZ, are internally flawless. If you know you plan on replacing it in a few years with a real diamond, then you really can't go wrong with either one! Just know that they are NOT diamonds and you should take a little extra care with them and clean them regularly to help keep them looking their best!
I'm sure some of the other members will chime in here, too, but I hope this helps in the meantime! Good luck with your decision!