In short, in my view these are the best value narrowband filters money can buy. I compared the Ha against a popular entry-level 7nm Ha filter and was very impressed with the greater clarity and contrast through the Antlia 3.5nm. These filters really allow you to get the best out of your mono camera, not to mention opening up the possibilities of shooting in less than ideal light conditions, such as a full Moon. There is some haloing around bright stars like Alnitak, but Antlia are very upfront about this and honestly it is better than I encountered with another Ha filter, so I have zero regrets or complaints.
The filters come very well packaged and protected, and you get the sense that they really care about their product and are not cutting corners, despite the very attractive pricing for these filters. I am so happy with them that I have since replaced my LRGB filters with a set of Antlias as well. If you're wanting to get into narrowband astrophotography and are hoping for a set of filters that will set you up for a long time without breaking the bank, seriously consider the 3.5nm Antlia set.
A note for users of the 294 sensor cameras (ASI294MM / QHY294M) - this sensor reacts weirdly when taking flats with Ha and S filters - do some quick googling and you'll confirm that it's your sensor, not the Antlia filters as it happens with all Ha and S narrowband filters. They do calibrate out just fine, you just need to be careful and precise when taking your flats.
Here are my first two narrowband images shot with these filters, NGC3342 and IC4628. Both shot on the ASI294MM-Pro from my Bortle 5 back yard in Eltham, Melbourne.