Something I've noticed in modern fighting sports is that a lot of the top talents are reaching their peak performances around the 30 year old mark, where as decades ago in boxing, you were pretty much considered past your prime after 25.
Masato in K1 is a good example I think. He was always considered a good fighter, but nothing special until he really turned it up in the later years.
A lot of the super fighters in boxing are all doing their best work now in their early thirties. Pacquiao, Mayweather, Martinez etc just to name a few. A similar scene in MMA too.
It's interesting to me that a lot of these guys are doing their best work, when they are only ever a few years away from being considered over the hill.