After playing for a few days cryo seems to be one of those classes which sounds pretty awesome, but is without the shadow of a doubt useless in pve.
While classes like pyro run around dropping aoe effect spells which stay around and potentially kill monsters en mass, cryo will stick to single hit spells with splash, on high cooldown and mediocre amount of monsters hit.
I can see how this class would be absolutely awesome in pvp, however in pve its borderline trash.
Why freeze a monster when you can just as easily stunlock it with a spell?
Why bother with icing when you can put down a persistent aoe spell and run around it, killing thing in masses?
To begin with, what the hell is the point of a defensive class in this game outside of pvp? Absolutely nothing.
Leveling is all about killing efficiently and cryo wont put a damn thing on the table there. Its running around ice piking twice, maybe icebolting for good measure and then goes on cooldown for the next 20 seconds.
Consider this a warning.
Cryo has potential in pvp, but if you intend to play pve or have a fetish involving ice, stay away from it, there is literally no point to it.