Well, Cheetah is a character who's feats are almost solely defined on the fact that she's a challenge for Diana (since the official super-speed stuff came much later). She doesn't have some anime-esk grand appearance of smashing a mountain in half with her face to hype up their fight, or taking out leagues of other heroes to show how tough she's going to be when she stumbles across Diana.
You know she's fast because she can hit Diana.
You know she's strong because Diana couldn't win the tug-of-war.
You know she's durable because she can take a hit from Diana.
That why it's not hard to believe that Cheetah is high on the power spectrum (for anyone who reads a WW comic anyway, or puts a single brain-cell behind why she's a WW rouge). I don't really need them destroying the landscape around them for that message to come across, although they do wreak a building in the second fight but I'm sure most people will still call that mild.
(Edit: Also Cheetah keeps getting scaled up every time Diana gets scaled up
)
I also like the final WW vs Genocide fight which is more stereotypical *punch-punch, kick-kick, up in to space, back down to earth*, but the WW vs Cheetah fights just got that classical feel to them I think.