My old aeon flow open version 1 needed a pad replacement and i decided to try something different with perforated pads and see if there is any sonic difference. As a reference, i listened with one notch filters as i found aeon treble very sharp and unnatural.
To my surprise the perforated pads make a significant sonic difference and i will describe them.
1. No need for one notch filter anymore. the treble hits the right spot now with ''bite'' but not in a fatiguing way, so you got all the detail retrieval from this driver.
2. Midrange is boosted and is not as dark as it was. It still has the silky smooth inviting sound to it but imagine it as just a bit darker than a HD650.
3. Soundstage definitely increased and now the open version sounds more ''open''. Closed version owners you get the point :)
4. Subbass is more apparent now because the boosted midbass is just at the right amount a bit reduced from the stock version
So for 70 euros you simply get a better headphone and a meaningful upgrade after all in my opinion. Its quite impressive what a sonic difference a different pad is making.
Hope that helps.