it's not hindering lower levels at all, it's putting the buff effects into proportion to the player level.
you know when you played final fantasy, and they had Fire/Fira/Firaga - scaling powers of spells. You couldn't use firaga before late into the game, and that was balanced and complied completely with common sense.
that's the sort of thing champion means. this is a really good idea as ive heard talks about buffs needing a nerf and realized it myself after using them, this idea with well-thought through level requirements would possibly even eliminate the need to even change the buff effects. if this was implemented it would also encourage more variation in the game, instead of the vast majority of clan-oriented play happening at 50-100.
i think 25/50/100 can definitely be improved upon, 200% of anything at 50 is still well powerful... level 50 seems too early to have double xp/kudos/fight speed. especially as they have the potential to stack with each other.
i think 25 is a nice place to start, since the early 30s can be grim before the exp drop if you cant beat terminatrix. the 200% buff perhaps could come at 70 or 75, with the final one at 120 or 130.
so 25/70/120 is what im leaning towards at the moment as a template.