She jumps X units at 300 MS. If she has 400 MS, she jumps 4/3*X units. If she has 556 MS, she jumps 556/300 units. If she has 230 MS, she jumps 230/300 MS. As it stands now, the following is true:
1. There is no point to getting furor on Kalista.
2. There is no point in slowing Kalista; as it stands now, she just jumps away if you slow her. Yeah, she can't walk very quickly, but she can just jump away very easily.
3. There is no point in buying +%MS on her or using MS quints
If units traveled is dependent on the current movespeed of kalista, then suddenly the following happens:
1. You can be mechanically better with Kalista by being able to jump at the very start of the furor buff instead of near the middle in order to maximize distance
2. Slows actually work on her mid and late game
3. Build %MS on her gives some benefit
4. There is now a reason to buy *something else besides zerker greaves* i.e. Swiftness on a Marksman. Zerker gives more raw dps, Swiftness gives more kiting potential. Both of them are fairly slight compared to the other
5. Crazy shit going on when you use Lulu! W + Shurelya's + Karma haste on Kalista.