After replacing Tenergy 05 with a new one it was like: ~1 week a little bit too fast, 7 weeks nice and stable, 1 week too soft/mushy (but not too slow). Replacement So yes, fresh one used to feel faster than a 2-3 month old one
ESN:
Tibhar MX-P - first week also a little bit too fast, but not as much as T 05 was, maybe more direct, so it might be not about speed that much, more about sponge hardness or what ever it was. And then each week I feel that sponge changes a little bit and I have to adjust to it.
Tibhar MX-D - speed difference is not that noticeable for me, more softening over time (again like you play some time with it and then you have to adjust a little bit each week), but I guess it still has that effect too.
Tibhar K3 - I just replaced it once. The first one felt fast and relatively soft (as for 52 degrees rubber) for like up to 2 weeks, then 2 weeks it was not bad, than it felt like a brick (still playable, but quite different to the first impressions), new one (compared to a 4 month old one) now again feels faster, easier to get speed and softer.
Andro Hexer, Donic Acuda S1 - both felt very nice from the very beginning, don't remember big difference in speed between 2-3 month old and a new one. I was much more concerned about that mushy feel I was started getting after 2-3 weeks.
Don't remember others good enough.
So I believe Tenergy has something in its sponge, but used to be quite stable after initial slowdown, Tibhar (ESN) has more of it and it wears out gradually without that longer stable period.
