As a fellow Fizz main (hey I'm even in a Fizz club on NA), I can say that the changes are pretty fun. His wave-shoving ability is way better with the new W, so you can be a bit more of a threat while your opponent roams. You have to max W now I think, so you don't get access to the better cooldown and spammability of the E until later (level13).
Getting used to holding W until the mark is cooked is really tricky, because you're probably in the habit of pressing Q-W at the same time or E-then W as you land. Now you just hold the W for the auto-reset and cooked mark damage.
The other nice thing is that, since you aren't maxing E as your primary damage tool, you don't have any mana issues. This means a lichbane rush is a little bit easier to do. Lichbane + cooked level 5 W is a surprisingly big chunk of burst. Add protobelt for that sweet bonus mobility and it's pretty solid.