Yeah the slowness of his spell flux makes him feel less useful. Who cares about the increase in range and mana ratio if you aren't going to hit the enemy champion?
Ryze can't farm with his E until he gets the tear or some considerable mana regen. Using your abilities to farm prior is just a waste of mana. I'd use E as a low damage poke before the changes and I could do that because the enemy had no time to move out of range. Now spell flux moves like Ryze's grandma.
Just doesn't feel right for his kit. He's supposed to be a burst mage. The addition of an active speed increase on his ult is pretty useless in most situations as well because you'd rather keep the ult for farm/team fights and the speed itself is hardly noticeable because during team fights you pretty much tank during the duration of your ult, you don't move. Having to choose whether to use his ult to run or tank is interesting, I guess, but meh.
If they felt Ryze was too tanky they should have just changed the ratios, not the abilities. If their aim was to get Ryze players to play less tanky to do more damage then they didn't have to reduce the range of his Q etc. and kill his ability to mid lane even more.